Cancer and the Cavalier King Charles Spaniel
- What It Is
- Forms of Dog Cancers
- What You Can Do
- Research News
- Related Links
- Veterinary Resources
While many cavalier King Charles spaniels develop cancer, and it is the breed’s second leading cause of death, few forms of cancer are more common in the CKCS than in other purebred breeds of dogs. The ones that are include anal sac gland carcinoma, squamous cell carcinoma, and diffuse large B-cell lymphoma (DLBCL), and are discussed below.
Here, we provide information about the forms of cancer most common to dogs, and to cavaliers in particular, as well as the causes of those cancers, if known, and current treatments. There are several other websites with far more detailed information on the topics of canine cancer. See Related Links below.
Cancer is a mutation of genes which normally control the growth of cells in the dog’s body. Cancer appears as the uncontrolled growth and division of abnormal cells and which are able to invade other tissues.
There are several types of cancer, including carcinoma (which begins in the skin or in tissues that line or cover internal organs), sarcoma (which begins in connective or supportive tissue, such as bone, muscle, cartilage, and blood vessels), leukemia (which begins in the bone marrow or other blood cell producing tissues and causes abnormal blood cells to enter the blood), lymphoma and myeloma (which begin in the cells of the immune system), mastocytoma (which begins on the skin), and central nervous system cancers (which begin in the brain and spinal cord), such as meningioma and neuroblastoma. There are other forms in addition to these.
A cancer often is named for the organ in which it first appears, but it can spread to other parts of the body through the blood system and lymph system. It starts as a mutation of a cell, likely due to radiation or chemical damage or a change in the cell’s genetic material. A mutation can affect the normal growth of that cell and its division into new cells, which also are mutated.
The mutated cells may form a mass, called a tumor (a neoplasm), which could be either malignant or benign. A benign tumor is not cancerous and often can be removed and not grow back or spread to other organs. A malignant tumor is one which continues to grow, often rapidly, invading the function of the organ, and which may spread to other parts of the body (metastasis). These cells also are regressive, non-specialized, and display a loss of structural and functional differentiation of normal cells.
Not all cancerous cells form tumors. Leukemia, for example, spreads through the blood system without creating a tumor.
Some forms of cancer are more common among dogs than others. They include:
• Osteosarcoma: This bone cancer may be discovered as a painful swelling within a bone, and is visible on an x-ray. However, it may already have grown so rapidly that it has spread to other organs, such as the lungs, by the time the swelling is first noticed. Osteosarcoma cells lack the strength of normal bone cells, and as they grow and replace the normal bone structure, they weaken the bone to the point that it will collapse.
• Lymphoma: Canine malignant lymphoma is a progressive, fatal disease caused by the malignant clonal expansion of lymphoid cells. Although lymphoid cell neoplastic transformation is not restricted to specific anatomic compartments, lymphoma most commonly arises from organized lymphoid tissues including the bone marrow, thymus, lymph nodes, and spleen. In addition to these primary and secondary lymphoid organs, common extranodal sites include the skin, eye, CNS, testis, and bone. Lymphoma is reported to be the most common hematopoietic neoplasm in dogs, with an incidence reported to approach 0.1% in susceptible, older dogs. Despite the prevalence of malignant lymphoma, its etiology remains poorly characterized. Hypothesized etiologies include retroviral infection, environmental contamination with phenoxyacetic acid herbicides, magnetic field exposure, chromosomal abnormalities, and immune dysfunction. A cavalier was included in a 2003 study of 25 dogs diagnosed with canine multicentric lymphoma, which also had chromosome imbalances. In a 2012 study, researchers reported that diffuse large B-cell lymphoma (DLBCL) "is prevalent in Cavalier King Charles Spaniel". A cavalier was included in a 2012 UK study of eleven dogs with rectal lymphoma.
In a January 2014 article, an 8-year old neutered female cavalier King Charles spaniel was found to have T-cell lymphoma which had spread through the nervous system to numerous organs. The researchers noted that heretofore, involvement of peripheral nerves in spreading neoplastic lymphocytes is very rare in any veterinary species.
In a 2015 article, a team of Bulgarian veterinarians treated a 6-month-old male cavalier King Charles spaniel for loss of vision and disorientation. The dog was placed under general anesthesia to perform electroretinography (ERG), which is a technique for diagnosing the functioning of the outer retina. The results showed that the retina was functioning normally. The dog had a series of difficulties in recovering from the anesthesia, resulting in its death after several hours. During necropsy, the researchers diagnosed metastatic thymoma, an extremely rare lymphocytic cancer in dogs.
• White blood cell.
• Mast cell tumor: histiocytic mastocytoma, mast cell sarcoma, mastocystosis. Mast cell tumors (right) account for about 10% of all skin tumors in dogs. Tumors on the perineum, digits, or prepuce in dogs appear to be more aggressive than those on the trunk. In an April 2013 report, a UK clinic found that cavaliers are "underrepresented" in terms of pre-disposition to developing mast cell tumors. In a May 2016 Japanese review, cavaliers reportedly had a relatively low incidence of mast cell tumors.
• Mammary tumor: tubular adenocarcinoma, papillary adenocarcinoma, papillary cystic adenocarcinoma, solid carcinoma, anaplastic carcinoma, fibrosarcoma. This is found largely in females. It appears as a lump beneath the skin on the breast. (See photo at right of a large mammary adeno-carcinoma; source: "Tails of a Shelter Vet".) In a 2011 report, the cavalier breed was identified as being at low-risk for mammary tumors. However, in a 2012 Swedish study, the researchers found that 15% of female cavalier King Charles spaniels developed mammary tumors by the age of ten years. In a May 2016 Japanese review, breast tumors amounted to 41.2% of all cancerous tumors found in CKCSs over an eight year period.
• Adrenal cortical tumor: This is a tumor of the cortisol-producing cells of the adrenal gland. It is known to cause a form of Cushing's Disease.
• Pituitary tumor: This tumor produces excessive amounts of ACTH -- adrenocorticotrophic hormone, the hormone which causes the adrenal glands to produce cortisol). It also is known to cause a form of Cushing's Disease.
• Anal sac gland carcinoma: A couple of studies of this form of cancer in cavaliers has been reported. One 2005 report and another in 2009. In the 2009 report, the author states that "English Cocker spaniels (and to a lesser extent Springer and Cavalier King Charles spaniels) are at higher risk of developing anal sac tumours than other dogs. This conclusion is based upon the analysis of large numbers of cases of anal sac tumours using data from veterinary pathology laboratories and breed registration data from The British Kennel Club." See also this January 2013 study.
• Squamous cell carcinoma: In both a 2008 study and a 2011 study of this cancer (right) in the cornea, which included three CKCSs, the authors found that it was related to chronic dry eye, which is a very common disorder in this breed. This form of carcinoma also is known to develop within the mouths and throats of cavaliers.
Also, see this 2011 report of a study of 44 dogs with tonsillar squarmous cell carcinoma, including four cavaliers. Additionally, see this 2013 report showing a cavalier with this disease, and this 2016 report on another CKCS with this disorder.
• Conjunctival hemangioma and hemangiosarcoma: In a 2006 study in which cavaliers were included, the authors concluded that ultraviolet light played a significant role in the cancer's development.
• Meningioma: In a 2010 report, a cavalier was found to have a meningioma in a post-mortem examination. The authors noted that, "isolated unilateral facial myokymia preceding diagnosis of a meningioma affecting facial nerve function within the caudal cranial fossa and the remarkably long duration of neurological signs (75 months) attributable to the neoplasm."
• Sebaceous gland adenocarcinoma.
• Acute lymphocytic leukemia: In a February 2012 report from North Carolina State University's veterinary school, a CKCS suffering from this cancer was treated with bone marrow containing peripheral blood progenitor cells which were extracted from a litter mate and transplanted into the patient.
• Melanoma: canine melanoma, oral melanoma. Typically, canine melanoma is found in the mouth (oral melanoma), on toes, behind the eyes, or on the skin, but it may develop anywhere.
The primary causes associated with the development and growth of cancerous cells are wide-ranging. They include:
• Exposure to certain forms and quantities of radiation.
• Exposure to certain chemicals which can damage cells’ genetic structure (mutagens and carcinogens in the environment and diet). in a 2012 study, lawn-care pesticides have been among those chemicals identified as increasing the risk of malignant lymphoma in dogs.
• Certain hormones, such as oestrogen and testosterone.
• Certain viruses.
• Genetic pre-disposition.
• Excessive stress and depression (yes, dogs can suffer both).
• A confused immune system.
• Neutering or not: Neutered male dogs reportedly have a "significantly increased risk for several forms of prostate cancer. In an August 2007 dog population study in the USA and Canada, researchers found that neutered males had "a significantly increased risk for each form of cancer ... urinary bladder transitional cell carcinoma (TCC), prostate adenocarcinoma (ACA), prostate TCC, prostate carcinoma (CA), and prostate tumors". They concluded that "Breed predisposition suggests that genetic factors play a role in the development of prostate cancer. The risk associated with being neutered is highest for TCC".
Hemangiosarcoma (HSA) is a cancer that is affected by neutering in females. cardiac HSA for spayed females was greater than 4 times that of intact females. A study on splenic HSA found the spayed females had more than 2 times the risk of developing this tumor as intact females. Intact females had a significantly lower risk of developing LSA (lymphoma) than neutered females or neutered males or intact males. A study on cutaneous mast cell tumors (MCT) in several dog breeds examined risk factors such as breed, size, and neuter status. The results showed a significant increase in frequency of MCT in neutered females; four times greater than that of intact females. See this February 2013 report.
In a In a February 2014 report about 2,505 Vizslas, researchers found that: (a) Mast cell cancer: 3.5 times higher incidence in neutered male and female dogs, independent of age at the time of neutering. (b) Hemangiosarcoma: 9.0 times higher incidence in neutered females compared to nonneutered females, independent of age at the time spaying was performed. No difference in incidence of this disease was found for neutered versus nonneutered males. (c) Lymphoma (lymphosarcoma): 4.3 times higher incidence in neutered male and female dogs, independent of age at the time of neutering. (d) Other types of cancer: 5.0 times higher incidence in neutered male and female dogs. The younger a dog was at the time of neutering the younger the age of the dog at the time the cancer was diagnosed. (e) All cancers combined: 6.5 times higher incidence of cancer in neutered females compared to nonneutered females; 3.6 times higher incidence of cancer in neutered males compared to nonneutered males.
• Not spaying and delayed spaying? It long had been reported that a female's risk of developing mammary cancer is greatly reduced by spaying, and the earlier the better. However, in a June 2012 review of all of these prior studies, the authors found that: "Due to the limited evidence available and the risk of bias in the published results, the evidence that neutering reduces the risk of mammary neoplasia, and the evidence that age at neutering has an effect, are judged to be weak and are not a sound basis for firm recommendations."
• Some medications. In both a 2008 study and a 2011 study, the researchers concluded that dogs (including cavaliers) treated with cyclosporine for dry eye are at risk to develop axial corneal squamous cell carcinoma.
• Possibly a consequence of surgery. In a 2010 report, a cavalier developed multiple inverted papilloma, which were benign tumors, following an ovariohysterectomy.
To some extent, dogs living longer lives are at greater risk of cancer eventually developing.
• Microchips? Do microchips induce cancer in dogs? The jury is out on this possible cause. Here is a link to a 2007 article, published in 2010, reviewing case reports.
See VetDepot's "Diagnosing Cancer in Dogs and Cats".
The form of treatment depends upon the form of the cancer. The options include:
• Chemotherapy, which consists of doses of toxic active ingredients that are intended to destroy rapidly dividing cancer cells but to spare the normal cells. Recent research has produced compounds of procaspase-3 activating compound 1 (PAC-1), which has been effective in killing lymphoma cells in dogs. See the reports discussed below herein: September 2010, October 2011, and January 2012.
• Monoclonal antibody (MAb) therapy may follow conventional chemotherapy, to treat T-cell lymphomas. Canine Lymphoma Monoclonal Antibody (CL/MAb 231) is a specific protein directed against canine lymphoma T-cells. It is used following a conventional chemotherapy regimen in an effort to prolong duration of remission.
• Stem cell transplants, using donor bone marrow containing peripheral blood progenitor cells, for treating dogs with lymphoma or lymphocytic leukemia. In a May 2015 article, US veterinarians successfully transplanted allogeneic hematopoietic stem cells from a littermate into a cavalier King Charles spaniel diagnosed with lymphocytic leukemia. The report states that the affected CKCS remained stable for at least two years.
• Radiation therapy, which is a beam of radiation aimed at the cancerous tumor.
• Surgery to remove tumors.
• Vaccines, including Oncept by Merial, is immunotherapy reportedly for dogs with stage II or III oral melanoma, to help achieve local disease control. Merial also has introduced a vaccine for treatment of B-cell lymphoma (DLBCL), which is designed to target CD20, a cell surface marker estimated to be expressed in about 70% of dogs with B-cell lymphoma.
• Electrocautery and cryosurgery.
• Hyperthermia, such as I-Therm treatments.
• Immunotherapy, including immune enhancement formula compounds, such as PetLife, which includes chrysin, Coriolus Versicolor, diindolymethane (DIM), Resveratrol, turmeric extract (curcumin), Quercetin, green tea extract, and l-selenium methionine.
• Prescriptive medications, such as: Palladia (toceranib phosphate), a tyrosine kinase inhibitor, used to treat mast cell tumors; and Oncept, a canine oral melanoma therapeutic vaccine, is a tyrosinase inhibitor.
• Holistic care can include some of the above modalities, such as hyperthermia and immunotherapy, as well as traditional Chinese medicine (TCM), herbal medicines, and types of palliative care. One form of TCM currently being studied is I’m-Yunity, a compound derived from the Coriolus versicolor mushroom.*
In a January 2015 report, researchers found lupeol eliminated recurrance of oral melanomas following partial surgical removal.
* Read more about
the Coriolus versicolor mushroom here.
• Palliative care, to manage the cancer and its symptoms, and improve quality of life, when cure is not an option.
May 2016: Cavaliers have high incidence of breast tumors and low incidence of mast cell tumors, in Japanese review. In a May 2016 article, Japanese researchers reviewed all canine cancer cases in one prefecture (equivalent to a state in the USA) between 2005 and 2012. Thirty-four cases involved cavalier King Charles spaniels. Of those, 41.2% of tumors in cavaliers were breast tumors. The lowest incidence in CKCSs was mast cell tumors.
March 2016: Cancerous thymus is found in 6-month old cavalier. In a 2015 article, a team of Bulgarian veterinarians (G. Simeonova, V. Nedev, R. Simeonov) treated a 6-month-old male cavalier King Charles spaniel for loss of vision and disorientation. The dog was placed under general anesthesia to perform electroretinography (ERG), which is a technique for diagnosing the functioning of the outer retina. The results showed that the retina was functioning normally. The dog had a series of difficulties in recovering from the anesthesia, resulting in its death after several hours. During necropsy, the researchers diagnosed metastatic thymoma, an extremely rare lymphocytic cancer in dogs.
May 2015: Cavalier overcomes lymphocytic leukemia with stem cells from littermate. In a May 2015 article, a team of US veterinarians and researchers (Steven E. Suter [right], Matthew J. Hamilton, Edmund W. Sullivan, Gopalakrishnan M. Venkataraman) successfully transplanted allogeneic hematopoietic stem cells from a littermate into a cavalier King Charles spaniel diagnosed with lymphocytic leukemia. The report states that the affected CKCS remained stable for at least two years.
January 2015: Japanese researchers find post-operative injection of lupeol eliminated recurrence of oral melanoma in a CKCS. In a January 2015 report, a team of Japanese researchers injected lupeol, a triterpene extracted from various fruits and vegetables that reportedly inhibits melanoma cell proliferation, in 11 dogs, including a 17-year-old cavalier, following partial (and one complete) surgical removal of oral malignant melanoma cancers. The usual post-operative treatment would have been radiation. There were no severe adverse effects, such as local pain, diarrhea, or vomiting, in any of the dogs during lupeol treatment. The treatment was successful in 10 of the 11 cases, including in the CKCS.
September 2014: Penn Vet School's "I'm-Yunity" doses appear to be succeeding in treating hemangiosarcoma cancer. In a September 2014 article in Penn Vet school's Bellweather magazine, the on-going research led by Dr. Dorothy Cimino Brown (see our November 2012 item below) appears to have been having favorable results in treating hemangiosarcoma. The treatments include a form of traditional Chinese medicine (TCM) called I’m-Yunity, a compound derived from the Coriolus versicolor mushroom.
If you want your dog to participate in this study, here is a link to the study's webpage.
February 2014: Pet food specialist links dry kibble to increase in pets' cancer. In a December 2013 article in Food Safety News, Barbara Royal, D.V.M., of The Royal Treatment Veterinary Center in Chicago, is concerned about how dry kibble is processed:
“The extrusion process (a high heat processing), creates two potent carcinogens, a heterocyclic amine and an acrylamide, which will be in every extruded kibble food, but certainly not be on the label. It is a byproduct of the extrusion process, and because it is not an ingredient that is added, it need not be put on the label,” she explains.
“So owners are unaware that, with every bite, they are feeding a potent carcinogen. I believe that this is one reason we are seeing such an increase in cancers in our pets.”
January 2014: Study of 2,500+ Vizslas find neutering results in "significantly increased odds" of developing certain cancers. In a February 2014 report in JAVMA of 2,505 Vizslas, researchers found that neutered males "had significantly increased odds of developing mast cell cancer, lymphoma, all other cancers, all cancers combined, and fear of storms, compared with the odds for sexually intact dogs." Neutered females "had significantly increased odds of developing hemangiosarcoma". Further, they found that the younger the age at neutering, "the earlier the mean age at diagnosis of mast cell cancer, cancers other than mast cell, hemangiosarcoma, lymphoma, all cancers combined, a behavioral disorder, or fear of storms."
January 2014: Cavalier dies of fast-spreading T-cell lymphoma through the nervous system. A team of Japanese veterinarians report in a January 2014 article about an 8-year old neutered female cavalier King Charles spaniel with T-cell lymphoma which had spread through the nervous system to numerous organs. They noted that heretofore, involvement of peripheral nerves in spreading neoplastic lymphocytes is very rare in any veterinary species.
April 2013: UK study finds CKCSs not pre-disposed to mast cell tumors. In an April 2013 report, a UK clinic has found that cavaliers are "underrepresented" in terms of pre-disposition to developing mast cell tumors. This study appears to contradict a 2012 Swedish study which reached an opposite finding.
February 2013: Neutering may affect dog's risk for developing certain cancers. A University of California at Davis study of golden retrievers has found that early neutering was associated with an increase in the occurrence of lymphosarcoma in males. Late neutering was associated with the subsequent occurrence of mast cell tumors and hemangiosarcoma in females.
January 2013: VetDC announces research for canine lymphoma drug. Veterinary Emerging Technologies Development Corporation (VetDC) has announced that is is funding the development of an anti-proliferative agent that preferentially targets lymphoid cells and works by inhibiting cellular DNA synthesis, leading to the induction of apoptosis, or programmed cell death. The agent is tagged VDC-1101. The drug was originally tested on dogs but was developed for human use. VetDC aims to make it available for dogs within two years.
In a prior study, VDC-1101 reportedly demonstrated substantial antitumor activity in dogs with both treatment-naïve and refractory lymphoma when administered on an every three-week schedule. Dr. David Vail, professor of oncology at the University of Wisconsin-Madison School of Veterinary Medicine, said “We are very encouraged by the results of this analysis, given the high unmet need for novel, effective veterinary anti-cancer agents, particularly in the refractory setting. These results indicate that VDC-1101 may be a powerful and convenient new therapeutic option for treating lymphoma in companion animals.” See VetDC's website for more information.
December 2012: Swedish study finds high percentage of mammary tumors in cavaliers. In a retrospective study (from 1995 through 2006) of Swedish dogs, the researchers found that 15% of female cavalier King Charles spaniels developed mammary tumors by the age of ten years.
November 2012: Penn Vet School extends its mushroom research. Penn Vet School has announced that it is enrolling patients into a new clinical trial for dogs with splenic hemangiosarcoma. Its press release states, "This trial will be evaluating the effects of a traditional chinese medicine supplement with anti-cancer properties." Obviously, this would be the Coriolus versicolor mushroom discussed below. Its announcement goes on: "A previous trial using the supplement significantly increased survival time in dogs with this type of cancer." Contact the researchers for more information: email@example.com or 215-573-0302.
November 2012: Mushroom compound extends life of dogs with cancer, study finds. In a 2012 study, Penn Vet School researchers reported that dogs with hemangiosarcoma that were given a compound derived from the Coriolus versicolor mushroom (Yun Zhi [I’m-Yunity]) (right) had the longest survival times ever reported for dogs with the disease.
In a later interview, researcher Dorothy Cimino Brown said:
“We were shocked. Prior to this, the longest reported median survival time of dogs with hemangiosarcoma of the spleen that underwent no further treatment was 86 days. We had dogs that lived beyond a year with nothing other than this mushroom as treatment”.
Shocked? In fact, Coriolus versicolor has been used as a medicinal mushroom in traditional Chinese medicine for over 2,000 years. The substance in the mushroom believed to be beneficial in fighting cancer is polysaccharopeptide, (PSP). The immune enhancement formula compound PetLife contains Coriolus versicolor.
August 2012: Lymphoma is reported to be prevalent in CKCS. Italian researchers report in Hematological Oncology that "Diffuse large B-cell lymphoma (DLBCL) is prevalent in Cavalier King Charles Spaniel".
June 2012: Early spaying does not mean reduced risk for mammary cancer. In a June 2012 review of studies of neutering and mammary cancer in dogs, the authors found that:
"Due to the limited evidence available and the risk of bias in the published results, the evidence that neutering reduces the risk of mammary neoplasia, and the evidence that age at neutering has an effect, are judged to be weak and are not a sound basis for firm recommendations."
February 2012: N. C. State University performs bone marrow transplant on a CKCS. Dr. Steven Suter, assistant professor of oncology at North Carolina State University, treated a cavalier King Charles spaniel named Zeke (pictured at left), suffering from acute lymphocytic leukemia (ALL), by transplanting bone marrow from his littermate Chip (pictured at right).
"We do require a donor, since we can not harvest progenitor cells from the patient. Leukemia patients have too many cancer cells floating around in their blood, so the machine would harvest them also. So, we find a matched donor who does not have cancer obviously, and harvest the cells from them,” Dr. Suter said. “We don't use this procedure regularly to treat dogs with leukemia ... we've treated two dogs with leukemia. We use it mainly to treat dogs with lymphoma, which is a very different disease."
He hopes that cases like Chip and Zeke will lead to a donor database for dogs, similar to the sort that people use. The typical cost of such a procedure is reportedly $15,000.00. Read more here.
January 2012: Some lawn care chemicals may increase the risk of canine malignant lymphoma. A 2012 report of a six-year study of 263 dogs at the Foster Hospital for Small Animals at Tufts University’s Cummings School of Veterinary Medicine, has shown that certain lawn pesticides (which were not identified in the study) may increase the risk of malignant lymphoma in dogs.
January 2012: Researchers find new anti-cancer PAC-1 compounds multi-fold more potent than PAC-1. PAC-1 researchers Danny C. Hsu, Howard S. Roth, Diana C. West, Rachel C. Botham, Chris J. Novotny, Steven C. Schmid, and Paul J. Hergenrother (at left in photo) report in a January 2012 study that PAC-1 compounds were "two- to four-fold more potent than PAC-1 and S-PAC-1 in cell culture, and thus have promise as experimental therapeutics for treatment of the many cancers that have elevated expression levels of procaspase-3." See also these October 2011 and September 2010 entries below.
Update: In an August 2013 newspaper article, Dr. Hergenrother stated that PAC-1 targets a cellular enzyme called procaspase-3 found at elevated levels in many forms of cancers, including those of the breast, colon, liver, lung, skin, blood and brain. "It gives cancer cells a signal to commit suicide," he said, but PAC-1 also spares the normal cells and can penetrate brain tumors.
December 2011: Good News: study finds CKCSs at low risk for mammary tumors. In a study by Norwegian canine geneticists of the identification of genetic variation in 11 candidate genes of canine mammary tumour, the the cavalier King Charles spaniel breed was identified as being at low-risk for mammary tumors.
October 2011: Univ. of Illinois researchers find PAC-1 compound signals canine lymphoma cancer cells to self-destruct. In an October 2011 report, University of Illinois researchers, led by chemistry professor Paul Hergenrother, have found that procaspase-3 activating compound 1 (PAC-1) acts as an anti-cancer agent which signals lymphoma cancer cells in canines to self-destruct. See also this September 2010 entry below.
In conclusion, PAC-1 is a small molecule that preferentially activates procaspase-3 to caspase-3, and induces apoptotic death in canine and human B-cell lymphoma lines. PAC-1 can be safely administered to research dogs and be consistently maintained at concentrations for prolonged periods of time which are predicted to exert anticancer effects.
February 2011: TGen needs spaniel DNA samples. The Translational Genomics Research Institute (TGen) seeks DNA samples from healthy spaniels to establish a genetic backdrop of healthy bloodlines against which genetic signatures of disease susceptibility can be deciphered and to perform periodic population surveys. Details are at http://www.tgen.org/research/canine-spaniel-frm.cfm
September 2010: PAC-1 anti-cancer compound found safe and effective in dogs with lymphoma. In a September 2010 study of a PAC-1 (procaspase-3 activating compound 1) derivative called S-PAC-1 (sulfonamide-PAC-1), the S-PAC-1 (administered as a 24- or 72-hour continuous IV infusion) in 6 pet dogs with spontaneously-occurring lymphoma revealed this compound to be safe in all 6 dogs and effective at reducing or stabilizing tumor growth in 4 out of 6 of them.
January 2009: Researchers seek DNA samples of cavaliers for anal sac gland carcinoma study. University of Cambridge veterinary oncologists are soliciting blood samples of cavaliers (and other spaniel breeds) either affected with anal sac gland carinoma or non-affected.
August 2007: Neutered male dogs reportedly have a "significantly increased risk for several forms of prostate cancer. In an August 2007 dog population study in the USA and Canada, researchers (Jeffrey N. Bryan, Matthew R. Keeler, Carolyn J. Henry, Margaret E. Bryan, Allen W. Hahn, Charles W. Caldwell) found that neutered males had "a significantly increased risk for each form of cancer ... urinary bladder transitional cell carcinoma (TCC), prostate adenocarcinoma (ACA), prostate TCC, prostate carcinoma (CA), and prostate tumors". They concluded that "Breed predisposition suggests that genetic factors play a role in the development of prostate cancer. The risk associated with being neutered is highest for TCC".
Chromosome aberrations in canine multicentric lymphomas detected with comparative genomic hybridisation and a panel of single locus probes. R Thomas, K C Smith, E A Ostrander, F Galibert, and M Breen. Brit J Cancer; Oct. 2003;89(8):1530–1537. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2394339/?tool=pmcentrez Quote: "Malignant lymphoma (lymphosarcoma) represents one of the most frequently encountered canine neoplasms, most commonly affecting middle-aged to older dogs of a wide range of breeds. The disease originates from the malignant transformation of developing lymphocytes, and in the absence of chemotherapy, survival beyond one month after diagnosis is uncommon. Although generally considered a chemoresponsive form of malignancy in the dog, .. the disease is highly heterogeneous at both the clinical and histological level. A proportion of cases demonstrate more favourable response to therapy, and longer overall survival time, than others receiving the same initial diagnosis. ... Since humans and dogs demonstrate extensive genome homology, it is likely that canine lymphoma will also be associated with recurrent chromosome aberrations. However, few reports exist describing chromosome abnormalities detected in canine lymphoma and at present insufficient data are available from which to draw significant conclusions on their findings. ... The development of comparative genomic hybridisation (CGH) as a technique for indirect analysis of chromosomal copy number changes in human tumour cells now provides a means by which imbalanced genomic aberrations can be identified accurately and efficiently without the need to generate tumour chromosome preparations. The application of CGH to the dog, the advent of novel molecular cytogenetic resources for this species, the development of comparative cytogenetic maps and the generation of an integrated canine genome map now provide a means by which to overcome prior practical difficulties and embark on more comprehensive studies of tumour karyotypes in this species. ... We have used CGH analysis to identify chromosome imbalances in 25 cases [including one cavalier King Charles spaniel] of canine multicentric lymphoma. The resulting range and distribution of aberrations observed indicates that, as with the human counterpart of this disease, the cytogenetic profiling of canine lymphoma as a potential aid to diagnosis and clinical management warrants more detailed investigation."
New aspects of canine pyometra. R. Hagman, Doctoral thesis, Swedish University of Agricultural Sciences, Uppsala, 2004. Quote: "Breeds with high risk of the development of pyometra in the present study were Collie (rough-haired), Rottweiler, Cavalier King Charles Spaniel, Bernese Mountain Dog and Golden Retriever. ... The interactions with biological age could be interpreted as that in some breeds (e.g. Rottweiler, rough-haired Collie, Golden Retriever, and Cavalier King Charles Spaniel), the risk of pyometra actually increases more and at an earlier age compared with other breeds. These breeds may carry a higher genetic predisposition for pyometra than other breeds."
Anal sac tumours of the dog and their response to cytoreductive surgery and chemotherapy. S.G. Emms. Austr Vet J; June 2005;83(6):340-343. Quote: "A retrospective study of anal sac tumours without pulmonary metastases, from the author's clinical records for the period July 1989 to July 2002, was conducted to establish the response to treatment with surgery and melphalan chemotherapy. Of 21 dogs [including cavalier King Charles spaniels] with tumours of the anal sacs 19 had apocrine gland adenocarcinomas of anal sac origin, one had a benign papillary cystadenoma and another had a malignant melanoma. Two of the 19 dogs had bilateral anal sac adenocarcinomas. Ten of the 19 dogs with apocrine gland adenocarcinomas of anal sac origin had sublumbar lymphadenopathy. Five dogs were excluded by their owners from recommended treatment. Fourteen dogs with apocrine gland adenocarcinomas of anal sac origin were treated by surgical cytoreduction and chemotherapy with melphalan. Seven of the 14 dogs had regional lymph node metastases. Cytoreduction was by local excision of the anal sac in all 14 dogs and concurrent removal of the sublumbar retroperitoneal lymph nodes in the seven dogs with regional lymph node metastases. The median survival time of dogs with sublumbar nodal metastasis was 20 months and for dogs with tumour localised to the anal sac the median survival time was 29.3 months. There was no difference in median survival of those dogs with sublumbar metastases compared to those without. This study suggests there is a role for melphalan in the treatment of dogs with anal sac adenocarcinoma when combined with cytoreductive surgery, with treatment survival times and the local recurrence rate of the primary tumour comparing favourably with previously published treatment regimes."
Primary Renal Neoplasia of Dogs. Jeffrey N. Bryan, Carolyn J. Henry, Susan E. Turnquist, Jeff W. Tyler, Julius M. Liptak, Scott A. Rizzo, Gabriella Sfiligoi, Steven J. Steinberg, Annette N. Smith, and Tarraca Jackson. J Vet Intern Med 2006;20:1155–1160. Quote: "Background: Primary renal tumors are diagnosed uncommonly in dogs. Hypothesis: Signs and survival will differ among different categories of primary renal tumors. Animals: Data were collected from the medical records of 82 dogs [including a cavalier King Charles spaniel] with primary renal tumors diagnosed by examination of tissue obtained by ultrasound-guided biopsy, needle aspiration, surgery, or at postmortem examination. Results: Forty-nine dogs had carcinomas, 28 had sarcomas, and 5 had nephroblastomas. The dogs were geriatric (mean 8.1 years; range: 1–17) with a weight of 24.9 kg (range: 4.5–80). Tumors occurred with equal frequency in each kidney with 4% occurring bilaterally. Initial signs included one or more of hematuria, inappetance, lethargy, weight loss, or a palpable abdominal mass. Pain was reported more frequently in dogs with sarcomas (5/28). The most common hematologic abnormalities were neutrophilia (22/63), anemia (21/64), and thrombocytopenia (6/68). Polycythemia was present in 3 dogs and resolved with treatment. Hematuria (28/49), pyuria (26/49), proteinuria (24/50), and isosthenuria (20/56) were the most frequently observed abnormalities on urinalysis. Pulmonary metastases were noted on thoracic radiographs in 16% of dogs at diagnosis. Seventy-seven percent of dogs had metastatic disease at the time of death. Median survival for dogs with carcinomas was 16 months (range 0–59 months), for dogs with sarcomas 9 months (range 0–70 months), and for dogs with nephroblastomas 6 months (range 0–6 months). Conclusions and Clinical Importance: Primary renal tumors in dogs are generally highly malignant with surgery being the "only treatment that improves survival."
Canine conjunctival hemangioma and hemangiosarcoma: a retrospective evaluation of 108 cases (1989–2004). Chris G. Pirie, Amy M. Knollinger, Chet B. Thomas, Richard R. Dubielzig. Vet Ophth; July 2006;9(4):215-226. Quote: "Canine conjunctival tumors of vascular endothelial origin are common, although under-reported. The purpose of this study was to evaluate the epidemiology of and potential risk factors for these tumors. This study evaluated 108 cases [including cavalier King Charles spaniels] (70 hemangiomas, 38 hemangiosarcomas) from 8300 canine submissions between 1989 and 2004. Signalment, location, pigmentation, size, duration, diagnosis, margins, ancillary therapy, and geographic location were recorded. Follow-up information was available for 49 cases. Each case was matched with two unaffected controls and compared using logistic regression analysis. Average age upon presentation was 8.6 years; there was no sex predilection. Risk of conjunctival tumors was statistically different among breed groups (P = 0.0010), demonstrating a propensity to occur in groups likely to have increased outdoor activity. Primary involvement occurred within nonpigmented epithelium along the leading edge of the nictitating membrane (41/108) and temporal bulbar conjunctiva (33/108). The etiology remains unknown; however, the strong site predilection, involvement of nonpigmented epithelium, and development within specific breed classes strongly suggest ultraviolet (UV) light as a significant risk factor. In a full-logistic model including breed, gender, age, and UV exposure, UV was not a statistically significant variable (P = 0.1215). In a reduced-model including UV only, significance was approached (P = 0.0696) and posthoc contrast demonstrated a significant linear trend with increasing UV exposure (P = 0.0147). In separate analysis of risks associated with hemangiosarcoma, compared with hemangioma, breed was not significant while increasing UV exposure was significant (P = 0.0381). Early surgical therapy is recommended and may be curative; however, recurrence is possible and more likely with hemangiosarcomas (11/20)."
Breed, gender and neutering status of British dogs with anal sac gland carcinoma. G. A. Polton, V. Mowat, H. C. Lee, K. A. Mckee, T. J. Scase. Vet & Comp Oncology; Sept 2006;4(3):125-131. Quote: "This study details the breed, gender and neutering status of a large cohort of British canine patients suffering from histologically confirmed anal sac gland carcinoma. Estimates of the relative risk for the development of this disease attributable to these factors are calculated. To reduce the impact of sampling errors, cases were selected from veterinary histopathology laboratories rather than referral hospital databases, and multiple estimates of the general British canine population were used. The weaknesses of the statistical assumptions made are discussed. There was no evidence to support a gender predisposition for the development of this condition. English cocker spaniels are significantly over-represented, with a mean relative risk estimate of 7.3. The mean relative risk estimate associated with being neutered was 1.4; the effect of neutering appeared to be more significant in male dogs compared with that in female dogs."
A population study of neutering status as a risk factor for canine prostate cancer. Jeffrey N. Bryan, Matthew R. Keeler, Carolyn J. Henry, Margaret E. Bryan, Allen W. Hahn, Charles W. Caldwell. The Prostate; August 2007;67(11):1174–1181. Quote: "Background: Prostate cancer has been reported to occur more commonly in neutered than intact male dogs in several case series. This study was undertaken to evaluate risk of prostate cancer in a large population database. The hypothesis was that castration is a risk factor for prostate cancer in male companion dogs. Methods: Data were derived from recorded visits to North American veterinary teaching hospitals. The Veterinary Medical Databases (VMDB) were queried to yield male dogs with urinary bladder transitional cell carcinoma (TCC), prostate adenocarcinoma (ACA), prostate TCC, prostate carcinoma (CA), and prostate tumors. A second query yielded all male dogs over the age of 4 years without a diagnosis of urinary tract cancer. These populations were compared to determine relative risks for developing each disease, singly and collectively, associated with neutering status. Odds ratios were calculated for breed as a risk factor. Results: Neutered males had a significantly increased risk for each form of cancer. Neutered males had an odds ratio of 3.56 (3.02–4.21) for urinary bladder TCC, 8.00 (5.60–11.42) for prostate TCC, 2.12 (1.80–2.49) for prostate adenocarcinoma, 3.86 (3.13–4.16) for prostate carcinoma, and 2.84 (2.57–3.14) for all prostate cancers. Relative risks were highly similar when cases were limited to those with a histologically confirmed diagnosis. Conclusions: Breed predisposition suggests that genetic factors play a role in the development of prostate cancer. The risk associated with being neutered is highest for TCC, supporting previous work identifying the urothelium and ductular rather than acinar epithelium as the source of these tumors."
Corneal squamous cell carcinoma in dogs with a history of chronic keratitis. R. R. Dubielzig, C. S. Schobert and J. Dreyfus. Vet Ophth; 2008;11(6):413–429 (Abstract 101). Quote: "Purpose: Corneal squamous cell carcinoma (SCC) is a rare tumor in dogs. The COPLOW has seen a recent increase in primary SCC in the axial cornea. We report here on 25 cases. Methods: Twenty-five cases of primary axial corneal SCC were selected from the COPLOW collection which includes more that 6000 neoplastic specimens. ... Results: The number of canine corneal SCC has risen in the past several years from 1 case per year from 1998 to 2004, jumping to 6 cases in 2005, 8 cases in 2006, and 7 cases in 2007. Brachycephalic breeds are overrepresented. The breed distribution included 8 Pugs, 5 Bulldog, 2 Boxers, 2 Greyhound, 2 Shi Tzu, 2 Border Collie, 2 Pekinese, 1 Bassett, 1 Chow, 1 Cocker, and 1 Cavalier King Charles Spaniel. No correlation to sex was found. Out of the 25 cases, 21 showed signs of chronic keratitis prior to developing SCC. In the remaining 4 cases the prior corneal history was unknown. Within the group of 25, 10 cases had been treated with cyclosporine alone, 4 with tacrolimus alone, 5 with both cyclosporine and tacrolimus, and 6 treated with other drugs or unknown. Follow-up information was obtained from 23 cases with a follow-up interval of between 5 days and 31 months (mean: 7.9 months). Three dogs had died for reasons unrelated to the ocular disease. One dog had recurrent disease extending deeply into the cornea. Conclusions: Brachycephalic dogs with a background of chronic keratitis that are treated with nonsteroidal antiinflammatory drugs are at risk to develop axial corneal SCC. The increase in annual cases of SCC suggests that this phenomenon is a developing problem."
Examining the heritability of anal sac gland carcinoma in cocker spaniels. Gerry Polton. J Sm Animal Prac; Jan 2009;50(1):57. Quote: "English cocker spaniels, and to a lesser extent springer and cavalier King Charles spaniels, are at higher risk of developing anal sac gland tumours than other dogs. ... If colleagues have encountered this tumour in an English cocker spaniel, a springer spaniel or a cavalier King Charles spaniel, it would be of great value to this project if a blood sample and/or the affected patient’s pedigree certificate could be submitted for inclusion in the analyses. ... For further information or to submit blood or pedigrees please contact Gerry Polton at North Downs Specialist Referrals, Friesian Building 3&4, Brewerstreet Dairy Business Park, Brewer Street, Bletchingley, Surrey RH1 4QP, UK. Tel: +44 (0) 1883 741440, Fax: +44 (0) 1883 347030. E-mail: firstname.lastname@example.org website: www.ndsr.co.uk"
Association between anal sac gland carcinoma and dog leukocyte antigen-DQB1 in the English Cocker Spaniel. J Aguirre-Hernández; G Polton; L J Kennedy; D R Sargan. Tissue antigens 2010;76(6):476-81. Quote: "Anal sac gland carcinomas occur frequently in English Cocker Spaniels and, to a lesser extent, in other spaniel breeds. The disease typically presents in dogs aged 8 years or older and frequently metastasises to the local lymph nodes. The association between anal sac gland carcinoma in English Cocker Spaniels and the major histocompatibility complex class II loci (the dog leukocyte antigen loci DLA-DRB1, -DQA1, -DQB1) was investigated in 42 cases and 75 controls. Based on a corrected error rate of 0.017 for each test, the allele distribution in DLA-DRB1 showed no significant difference between cases and controls (P value = 0.019), while a significant difference was obtained for DLA-DQA1 and -DQB1 alleles (P values are 0.010 and 3.3 × 10⁻⁵). The DLA-DQB1*00701 allele was the most common in both cases and controls, but it had a higher frequency among the former (0.89) than in the latter (0.61), while the second most common allele had a higher frequency in the controls (0.23) than in the cases (0.07). Haplotype distributions were also significantly different between the two groups (P value = 1.61 × 10⁻⁴). This is the second disease in English Cocker Spaniels for which the most common DLA-DQB1 allele in the breed has been shown to have a higher frequency in cases than controls, while the second most common allele in the breed (*02001) has a significantly higher frequency in the controls, compared with the cases."
The development of multiple cutaneous inverted papilloma following ovariohysterectomy in a dog. Munday, J.S.; French, A.F.; MacNamara, A.R. N.Zeal. Vet. J.; June 2010;58(3):168-171(4). Quote: "Case History: Ovariohysterectomy was performed on an adult Cavalier King Charles Spaniel. The skin that had been clipped for surgery was noticed to be erythematous 8 days later. Clinical and Pathological Findings: Poorly defined patches containing multiple papules were visible bilaterally within the clipped skin. These became larger over the following 2 weeks, and samples were collected for histology. Seven days later, the lesions were multiple raised masses, up to 5 cm in diameter. Histology revealed numerous cup-shaped epidermal proliferations extending into the dermis. The presence of keratin ocytes with increased quantities of blue-grey cytoplasm, and koilocytosis suggested papillomaviral infection; Canis familiaris papillomavirus (CfPV-2) DNA was amplified from two separate samples. Complete regression was observed 8 weeks after the lesions had been initially observed. Diagnosis: Multiple inverted papilloma confined to skin that had been clipped for surgery. Clinical Relevance: This is the first time that the development of canine cutaneous papillomas has been associated with surgery. The nature of the association between surgery and development of the papillomas is uncertain. However, it is possible that damage to superficial skin could promote the formation of papillomas. This is the first identification of CfPV-2 in New Zealand."
Microchip-induced tumors in laboratory rodents and dogs: A review of the literature 1990–2006. Katherine Albrecht. IEEE Int'l Symposium. June 2010;337-349. Quote: This paper reviews literature published in oncology and toxicology journals between 1990 and 2006 addressing the effects of implanted radio-frequency (RFID) microchips on laboratory rodents and dogs. Eleven articles were reviewed in all, with eight investigating mice and rats, and three investigating dogs. In all but three of the articles, researchers observed that malignant sarcomas and other cancers formed around or adjacent to the implanted microchips. The tumors developed in both experimental and control animals, and in two household pets. In nearly all cases, researchers concluded that the microchips had induced the cancers. Possible explanations for the tumors are explored, and a set of recommendations for policy makers, human patients and their doctors, veterinarians, pet owners, and oncology researchers is presented in light of these findings.
Unilateral facial myokymia in a dog with an intracranial meningioma. Holland, CT; Holland, JT; Rozmanec, M. Austr Vet J; Sept 2010;88(9):357-361(5). Quote: "A 23-month-old castrated male Cavalier King Charles spaniel was evaluated because of a 6-month history of unusual rippling/undulating movements of the right facial muscles that were continuous and persisted during sleep. Neurological examination revealed narrowing of the right palpebral fissure and unilateral right-sided facial myokymia that was characterised by myokymic, and to a lesser degree, neuromyotonic discharges on concentric needle electromyographic examination. After persisting unchanged for almost 2.5 years from its onset, the facial myokymia gradually disappeared over a 6-month period concomitant with the emergence of a persistent ipsilateral facial paralysis and head tilt. At 5 years and 9 months after the first examination, signs of ipsilateral lacrimal, pharyngeal and laryngeal dysfunction became evident and the dog was euthanased. Postmortem examination identified a malignant (WHO grade III) meningioma in the right cerebellopontomedullary angle that compressed the ventrolateral cranial medulla, effaced the jugular foramen and internal acoustic meatus and extended into the facial canal of the petrous temporal bone. Novel findings were the unique observation of isolated unilateral facial myokymia preceding diagnosis of a meningioma affecting facial nerve function within the caudal cranial fossa and the remarkably long duration of neurological signs (75 months) attributable to the neoplasm."
Discovery and Canine Preclinical Assessment of a Nontoxic Procaspase-3–Activating Compound. Quinn P. Peterson, Danny C. Hsu, Chris J. Novotny, Diana C. West, Dewey Kim, Joanna M. Schmit, Levent Dirikolu, Paul J. Hergenrother, Timothy M. Fan. J.CancerRes. Sept. 2010;70:7232-7241. Quote: "A critical event in the apoptotic cascade is the proteolytic activation of procaspases to active caspases. The caspase autoactivating compound PAC-1 induces cancer cell apoptosis and exhibits antitumor activity in murine xenograft models when administered orally as a lipid-based formulation or implanted s.c. as a cholesterol pellet. However, high doses of PAC-1 were found to induce neurotoxicity, prompting us to design and assess a novel PAC-1 derivative called S-PAC-1. Similar to PAC-1, S-PAC-1 activated procaspase-3 and induced cancer cell apoptosis. However, S-PAC-1 did not induce neurotoxicity in mice or dogs. Continuous i.v. infusion of S-PAC-1 in dogs led to a steady-state plasma concentration of ∼10 μmol/L for 24 to 72 hours. In a small efficacy trial of S-PAC-1, evaluation of six pet dogs with lymphoma revealed that S-PAC-1 was well tolerated and that the treatments induced partial tumor regression or stable disease in four of six subjects. Our results support this canine setting for further evaluation of small-molecule procaspase-3 activators, including S-PAC-1, a compound that is an excellent candidate for further clinical evaluation as a novel cancer chemotherapeutic."
Superficial corneal squamous cell carcinoma occurring in dogs with chronic keratitis. Jennifer Dreyfus, Charles S. Schobert, Richard R. Dubielzig. Vet Ophth; May 2011;14(3):161-168. Quote: "Objective: Canine corneal squamous cell carcinoma (SCC) is a rare tumor, with only eight cases previously published in the veterinary literature. The Comparative Ocular Pathology Lab of Wisconsin (COPLOW) has diagnosed 26 spontaneously occurring cases, 23 in the past 4 years [three of which were cavalier King Charles spaniels]. This retrospective study describes age and breed prevalence, concurrent therapy, biologic behavior, tumor size and character, and 6-month survival rates after diagnosis. Results: A search of the COPLOW database identified 26 corneal SCC cases diagnosed from 1978 to 2008. There is a strong breed predilection (77%) in brachycephalic breeds, particularly those prone to keratoconjunctivitis sicca. The mean age was 9.6 years (range 6–14.5 years). Follow-up information >6 months was available for 15 of 26 cases. Recurrence occurred in the same eye in nine cases, seven of which were incompletely excised at the time of first keratectomy. No cases were known to have tumor growth in the contralateral eye and no cases of distant metastases are known. Where drug history is known, 16 of 21 dogs had a history of treatment with topical immunosuppressive therapy (cyclosporine or tacrolimus) at the time of diagnosis. Conclusion: Chronic inflammatory conditions of the cornea and topical immunosuppressive therapy may be risk factors for developing primary corneal SCC in dogs. SCC should be considered in any differential diagnosis of corneal proliferative lesions. Superficial keratectomy with complete excision is recommended, and the metastatic potential appears to be low."
Canine tonsillar squamous cell carcinoma - a multi-centre retrospective review of 44 clinical cases. A Mas, L Blackwood, P Cripps, S Murphy, J De Vos, N Dervisis, M Martano, G A Polton. J Small Anim Pract. 2011 Jul ;52 (7):359-364. Quote: " Objectives: To review the presenting clinical signs, treatment and survival of dogs with tonsillar squamous cell carcinoma and, if possible, to identify useful prognostic indicators. Methods: Medical records of 44 dogs were reviewed retrospectively. ... The breeds included: ... cavalier King Charles spaniel (four) ... Clinical signs, clinical stage, time of diagnosis, treatment and outcome were recorded. Data were analysed using the Kaplan-Meier, log-rank, Student's t test, Kruskal-Wallis test and Chi-square/Fisher Exact test as appropriate. Results: The most frequent clinical signs were cough (12 dogs, 27%), enlarged lymph nodes (11 dogs, 25%) and dysphagia (11 dogs, 25%). Anorexia and lethargy were less common but were significantly associated with a poor outcome. No matter what treatment modalities were used, survival times were short and median survival time for all the dogs in the study was 179 days. However, there were a small number of long-term survivors. Clinical Significance: Dogs with tonsillar squamous cell carcinoma that suffered anorexia and lethargy had shorter survival times than patients without these clinical signs. Although surgery, chemotherapy and radiotherapy seem to increase the median survival time of dogs diagnosed with tonsillar squamous cell carcinoma, there is no highly effective treatment for canine tonsillar squamous cell carcinoma."
Dog models of naturally occurring cancer. Jennie L. Rowell, Donna O. McCarthy, Carlos E. Alvarez. Trends in Molecular Med. July 2011;17(7):380-388. Quote: "Studies using dogs provide an ideal solution to the gap in animal models for natural disease and translational medicine. This is evidenced by approximately 400 inherited disorders being characterized in domesticated dogs, most of which are relevant to humans. There are several hundred isolated populations of dogs (breeds) and each has a vastly reduced genetic variation compared with humans; this simplifies disease mapping and pharmacogenomics. Dogs age five- to eight-fold faster than do humans, share environments with their owners, are usually kept until old age and receive a high level of health care. Farseeing investigators recognized this potential and, over the past decade, have developed the necessary tools and infrastructure to utilize this powerful model of human disease, including the sequencing of the dog genome in 2005. Here, we review the nascent convergence of genetic and translational canine models of spontaneous disease, focusing on cancer."
Pharmacokinetics and derivation of an anticancer dosing regimen for PAC-1 in healthy dogs. Pamela W. Lucas, Joanna M. Schmit, Quinn P. Peterson, Diana C. West, Danny C. Hsu, Chris J. Novotny, Levent Dirikolu, Daniel R. Deorge, Laura D. Garrett, Paul J. Hergenrother, and Timothy M. Fan. Invest New Drugs. 2011 October; 29(5): 901–911. Quote: "PAC-1 [procaspase-3 activating compound 1] is a preferential small molecule activator of procaspase-3 and has potential to become a novel and effective anticancer agent. The rational development of PAC-1 for translational oncologic applications would be advanced by coupling relevant in vitro cytotoxicity studies with pharmacokinetic investigations conducted in large mammalian models possessing similar metabolism and physiology as people. In the present study, we investigated whether concentrations and exposure durations of PAC-1 that induce cytotoxicity in lymphoma cell lines in vitro can be achievable in healthy dogs through a constant rate infusion (CRI) intravenous delivery strategy. Time- and dose-dependent procaspase-3 activation by PAC-1 with subsequent cytotoxicity was determined in a panel of B-cell lymphoma cells in vitro. The pharmacokinetics of PAC-1 administered orally or intravenously was studied in 6 healthy dogs using a crossover design. The feasibility of maintaining steady state plasma concentration of PAC-1 for 24 or 48 hours that paralleled in vitro cytotoxic concentrations was investigated in 4 healthy dogs. In vitro, PAC-1 induced apoptosis in lymphoma cell lines in a time- and dose-dependent manner. The oral bioavailability of PAC-1 was relatively low and highly variable (17.8 ± 9.5%). The achievement and maintenance of predicted PAC-1 cytotoxic concentrations in normal dogs was safely attained via intravenous CRI lasting for 24 or 48 hours in duration. Using study, we investigated whether concentrations and exposure durations of PAC-1 that induce cytotoxicity in lymphoma cell lines in vitro can be achievable in healthy dogs through a constant rate infusion (CRI) intravenous delivery strategy. Time- and dose-dependent procaspase-3 activation by PAC-1 with subsequent cytotoxicity was determined in a panel of B-cell lymphoma cells in vitro. The pharmacokinetics of PAC-1 administered orally or intravenously was studied in 6 healthy dogs using a crossover design. The feasibility of maintaining steady state plasma concentration of PAC-1 for 24 or 48 hours that paralleled in vitro cytotoxic concentrations was investigated in 4 healthy dogs. In vitro, PAC-1 induced apoptosis in lymphoma cell lines in a time- and dose-dependent manner. The oral bioavailability of PAC-1 was relatively low and highly variable (17.8 ± 9.5%). The achievement and maintenance of predicted PAC-1 cytotoxic concentrations in normal dogs was safely attained via intravenous CRI lasting for 24 or 48 hours in duration. Using the dog as a large mammalian model, PAC-1 can be safely administered as an intravenous CRI while achieving predicted in vitro cytotoxic concentrations."
Malocclusion associated with macroglossia in a dog. Gerhard Putter. Comp. Anim. Nov/Dec 2011;16(9):12-19. Quote: "Macroglossia (defined as enlargement of the tongue but not indicating the cause) is a rare condition in dogs. The association with malocclusion has not been described before. It has been reported that resection of as much as 60% of the body of the tongue is well tolerated by dogs. Although the tongue is a very vascular organ, intraoperative haemorrhage during tongue amputation can be effectively controlled by a tourniquet at the base of the tongue. Healing of the amputation wound is usually rapid and uneventful. ... A five year old, 12 kg neutered male Cavalier King Charles Spaniel was presented with a complaint of an excessively long tongue."
Identification of genetic variation in 11 candidate genes of canine mammary tumour. K. S. Borge, A. L. Børresen-Dale, F. Lingaas. Vet. & Comp. Oncology; Dec 2011;9(4):241-250. Quote: "The incidence of canine mammary tumours (CMTs) differs significantly between breeds [cavalier King Charles spaniels are identified as being at low-risk for CMT], strongly supporting an influence of genetic risk factors. We aimed at identifying germline genetic variations in mammary tumour-associated genes in dogs and survey whether these might alter the encoded proteins. We sequenced 11 genes (BRCA1, BRCA2, BRIP1, CDH1, CHEK2, EGFR, ESR1, HER2, PTEN, STK11 and TP53) and screened for genetic variations. Sixty-four single nucleotide polymorphisms (SNPs) were identified. Nine of the coding SNPs were non-synonymous, of which four were located in gene regions conserved across four species. Three of the non-synonymous SNPs might be damaging according to PolyPhen predictions. One of the indels identified has previously been associated with CMTs. Because of the founder effects, genetic drift and inbreeding in many dog breeds the allele frequencies of the genes studied are likely to vary significantly between breeds and contribute to the considerable difference in genetic risk associated with cancer."
Thymidine kinase assay in canine lymphoma. J. W. Elliott, P. Cripps, L. Blackwood. Vet. & Comp. Oncology; Dec 2011. Quote: "The aim of the study was to evaluate if thymidine kinase (TK) correlated with duration of first remission (DFR) or survival in dogs with lymphoma and if initial TK levels correlated with stage and substage; and also to assess if TK level at diagnosis correlated with immunophenotype. TK was assayed in 73 dogs with treatment naïve lymphoma, then again after treatment; 47% had an initial TK above the reference interval. Dogs with B-cell lymphoma had higher initial TK activities than dogs with T-cell lymphoma. TK levels were not higher in dogs with higher stage disease and TK activity prior to treatment was not associated with DFR or survival. Where TK was elevated at diagnosis, it fell into the reference range during remission. TK was normal in 53% dogs at diagnosis, which is higher than previously reported. Further studies are warranted to assess the utility of TK in dogs with lymphoma."
Parallel Synthesis and Biological Evaluation of 837 Analogues of Procaspase-Activating Compound 1 (PAC-1). Danny C. Hsu, Howard S. Roth, Diana C. West, Rachel C. Botham, Chris J. Novotny, Steven C. Schmid, Paul J. Hergenrother. ACS Comb Sci. 2012 January; 14(1):44–50. Quote: "Procaspase-Activating Compound 1 (PAC-1) is an ortho-hydroxy N-acyl hydrazone that enhances the enzymatic activity of procaspase-3 in vitro and induces apoptosis in cancer cells. An analogue of PAC-1, called S-PAC-1, was evaluated in a veterinary clinical trial in pet dogs with lymphoma and found to have considerable potential as an anticancer agent. With the goal of identifying more potent compounds in this promising class of experimental therapeutics, a combinatorial library based on PAC-1 was created, and the compounds were evaluated for their ability to induce death of cancer cells in culture. For library construction, 31 hydrazides were condensed in parallel with 27 aldehydes to create 837 PAC-1 analogues, with an average purity of 91%. The compounds were evaluated for their ability to induce apoptosis in cancer cells, and through this work, six compounds were discovered to be substantially more potent than PAC-1 and S-PAC-1. These six hits were further evaluated for their ability to relieve zinc-mediated inhibition of procaspase-3 in vitro. In general, the newly identified hit compounds are two- to four-fold more potent than PAC-1 and S-PAC-1 in cell culture, and thus have promise as experimental therapeutics for treatment of the many cancers that have elevated expression levels of procaspase-3.
Household chemical exposures and the risk of canine malignant lymphoma, a model for human non-Hodgkin’s lymphoma. Biki B. Takashima-Uebelhoer, Lisa G. Barber, Sofija E. Zagarins, Elizabeth Procter-Gray, Audra L. Gollenberg, Antony S. Moore, Elizabeth R. Bertone-Johnson. Environmental Research. Jan 2012.; 112:171-176. Quote: "Background: Epidemiologic studies of companion animals offer an important opportunity to identify risk factors for cancers in animals and humans. Canine malignant lymphoma (CML) has been established as a model for non-Hodgkin’s lymphoma (NHL). Previous studies have suggested that exposure to environmental chemicals may relate to development of CML. Methods: We assessed the relation of exposure to flea and tick control products and lawn-care products and risk of CML in a case–control study of dogs presented to a tertiary-care veterinary hospital (2000–2006). Cases were 263 dogs with biopsy-confirmed CML. Controls included 240 dogs with benign tumors and 230 dogs undergoing surgeries unrelated to cancer. Dog owners completed a 10-page questionnaire measuring demographic, environmental, and medical factors. Results: After adjustment for age, weight, and other factors, use of specific lawn care products was associated with greater risk of CML. Specifically, the use of professionally applied pesticides was associated with a significant 70% higher risk of CML (odds ratio(OR)=1.7; 95% confidence interval (CI)=1.1–2.7). Risk was also higher in those reporting use of self-applied insect growth regulators (OR=2.7; 95% CI=1.1–6.8). The use of flea and tick control products was unrelated to risk of CML. Conclusions: Results suggest that use of some lawn care chemicals may increase the risk of CML. Additional analyses are needed to evaluate whether specific chemicals in these products may be related to risk of CML, and perhaps to human NHL as well."
The effect of neutering on the risk of mammary tumours in dogs – a systematic review. W. Beauvais, J. M. Cardwell and D. C. Brodbelt. J.Sm.Anim.Pract, June 2012; 53(6): 314-322. Quote: "A commonly-stated advantage of neutering bitches is a significant reduction in the risk of mammary tumours, however the evidence for this has not previously been assessed by systematic review. The objectives of this study were to estimate the magnitude and strength of evidence for any effect of neutering, or age of neutering, on the risk of mammary tumours in bitches. A systematic review was conducted based on Cochrane guidelines. Peer-reviewed analytic journal articles in English were eligible and were assessed for risk of bias by two reviewers independently. Of 11,149 search results, 13 reports in English-language peer-reviewed journals addressed the association between neutering/ age at neutering and mammary tumours. Nine were judged to have a high risk of bias. The remaining four were classified as having a moderate risk of bias. One study found an association between neutering and a reduced risk of mammary tumours. Two studies found no evidence of an association. One reported “some protective effect” of neutering on the risk of mammary tumours, but no numbers were presented. Due to the limited evidence available and the risk of bias in the published results, the evidence that neutering reduces the risk of mammary neoplasia, and the evidence that age at neutering has an effect, are judged to be weak and are not a sound basis for firm recommendations."
The dog as a possible animal model for human non-Hodgkin lymphoma: a review. Laura Marconato, Maria Elena Gelain, Stefano Comazzi. Hematological Oncology. 2012. Quote: "Lymphoma represents the most frequent hematopoietic cancer in dogs, and it shows significant overlap with the human disease. ... Diffuse large B-cell lymphoma ... DLBCL is prevalent in Cavalier King Charles Spaniel and Bassethound ... Several environmental factors have been associated with canine lymphoma, suggesting that they may contribute to lymphomagenesis. Canine lymphoma often presents in advanced stage (III–V) at diagnosis and, most commonly, has an aggressive clinical course requiring prompt treatment, which relies on the use of polychemotherapy. In this review, we will summarize the state-of-the-art of canine lymphoma epidemiology, pathobiology, diagnostic work-up and therapy, and will highlight the links to the corresponding human disease, providing evidence for the use of dog as an animal model of spontaneous disease."
Squamous papilloma in an older Cavalier King Charles. Sing Kong Yuen. Aug. 2012. SinPets.com
Rectal lymphoma in 11 dogs – a retrospective study. N. Van den Steen, D. Berlato, G. Polton, J. Dobson, J. Stewart, G. Maglennon, A. M. Hayes and S. Murphy. J.Sm.Anim.Prac. Aug 2012. Quote: "Objectives: To retrospectively evaluate the clinical behaviour and immunophenotype of lymphoma of the rectum in dogs. Methods: Eleven dogs [including a cavalier King Charles spaniel] diagnosed with lymphoma of the rectum on histopathology were retrospectively reviewed. Immunohistochemistry with CD3 and CD79a antibodies was performed at diagnosis or retrospectively. Results: Treatment protocol varied with six dogs undergoing surgery and adjuvant chemotherapy, two received chemotherapy after only incisional biopsy, one had surgical resection only, one was treated symptomatically and one dog was not treated. Chemotherapy treatment consisted of either a -low-dose COP (cyclophosphamide - prednisolone - vincristine) protocol (four dogs) or a six-week CHOP-based (cyclophosphamide - vincristine - -prednisolone - anthracycline) protocol (four dogs). Dogs that received chemotherapy lived significantly longer than dogs that did not receive chemotherapy (2352 versus 70 days). Median survival time was not reached, and there was an overall mean survival time of 1697 days. Immuno-histochemistry was performed in 10 of 11 samples, and was consistent with B-cell -lymphoma in all cases. Clinical Significance: Canine lymphoma of the rectum is associated with a favourable prognosis. Immunohistochemical evaluation of these lesions was consistent with B-cell lymphoma in all cases in which it was examined."
Single Agent Polysaccharopeptide Delays Metastases and Improves Survival in Naturally Occurring Hemangiosarcoma. Dorothy Cimino Brown and Jennifer Reetz. Evidence-Based Complementary and Alternative Medicine 2012; Article ID 384301. Quote: "The 2008 World Health Organization World Cancer Report describes global cancer incidence soaring with many patients living in countries that lack resources for cancer control. Alternative treatment strategies that can reduce the global disease burden at manageable costs must be developed. Polysaccharopeptide (PSP) is the bioactive agent from the mushroom Coriolus versicolor (right). Studies indicate PSP has in vitro antitumor activities and inhibits the growth of induced tumors in animal models. Clear evidence of clinically relevant benefits of PSP in cancer patients, however, is lacking. The investment of resources required to complete large-scale, randomized controlled trials of PSP in cancer patients is more easily justified if antitumor and survival benefits are documented in a complex animal model of a naturally occurring cancer that parallels human disease. Because of its high metastatic rate and vascular origin, canine hemangiosarcoma is used for investigations in antimetastatic and antiangiogenic therapies. In this double-blind randomized multidose pilot study, high-dose PSP significantly delayed the progression of metastases and afforded the longest survival times reported in canine hemangiosarcoma. These data suggest that, for those cancer patients for whom advanced treatments are not accessible, PSP as a single agent might offer significant improvements in morbidity and mortality."
Breed Variations in the Incidence of Pyometra and Mammary Tumours in Swedish Dogs. S. Jitpean, R. Hagman, B. Ström Holst, O.V. Höglund, A. Pettersson, A. Egenvall. Reproduction in Domestic Animals. Dec. 2012. Quote: "Dogs enrolled in a Swedish insurance company (during 1995–2006) were studied for development of pyometra and mammary tumours (MTs), with special attention to breed and age. There were over 260 000 female dogs with over 1 000 000 dog-years at risk (DYAR) in the database, using data on bitches up to 10 years of age and 110 breeds with over 1000 DYAR. In total, 20 423 bitches were diagnosed with pyometra and 11 758 with MTs and 30 131 with either or both of the two diseases. [48% of female cavalier King Charles spaniels developed pyometra, and 15% of them developed mammary tumors, and 54% of them developed either or both pyometra and mammary tumors, by the age of ten years.] The incidence rate (IR) for pyometra was 199 (95% CI 196–202), for MTs 112 (95% CI 110–114) and for either or both of the two diseases 297 (95% CI 294–301) dogs per 10 000 DYAR. The mean age of diagnosis pyometra was 7.0 years (SD ± 2.2), MTs 8.0 years (SD ± 1.6). In all breeds, the overall proportion of the bitches that developed disease by 10 years of age was for pyometra 19%, MTs 13%, and either or both of two diseases 30%. The top 10 breeds diagnosed with either or both of the two diseases were the Leonberger (73%), Irish Wolfhound (69%), Bernese Mountain Dog (69%), Great Dane (68%), Staffordshire Bull Terrier (66%), Rottweiler (65%), Bullterrier (62%), Doberman (62%), Bouvier des Flandres (60%), Airdaleterrier (60%). These data provide information of the combined disease incidence in a large number of different breeds. Breed variations in incidence rate suggests genetic components in disease development. Our study may be valuable in the search for genetic risk-factors or protective factors."
Evaluation of an anal sac adenocarcinoma tumor in a Spitz dog. Javad Javanbakht, Abbas Tavassoli, Atefeh Sabbagh, Mehdy Aghamohammmad Hassan, Shohreh Alian Samakkhah, Radmehr Shafiee, Ali Lakzian, Vahideh Rahmani Ghalee, and Sonia Shoja Gharebagh. Asian Pac J Tropical Biomed. Jan. 2013; 3(1):74-78. Quote: "Anal Gland Adenocarcinoma is a cancer of the apocrine gland, located inside of the anal sac. Canine anal glands are scent glands that produce an oily secretion. They are found on either side of the dog's anus between the internal and external sphincter. These tumors tend to be locally invasive and can metastasize early. However, this cancer is associated with a prolonged clinical course. Breeds more commonly affected include English Cocker Spaniels, Cavalier King Charles Spaniels, German Shepherds and English Springer Spaniels. Both genders of dogs are equally affected. The cause of this tumor is unknown."
Breed-Predispositions to Cancer in Pedigree Dogs. Jane M. Dobson. ISRN Vet.Sci. 2013. Quote: "Cancer is a common problem in dogs and although all breeds of dog and crossbred dogs may be affected, it is notable that some breeds of pedigree dogs appear to be at increased risk of certain types of cancer suggesting underlying genetic predisposition to cancer susceptibility. Although the aetiology of most cancers is likely to be multifactorial, the limited genetic diversity seen in purebred dogs facilitates genetic linkage or association studies on relatively small populations as compared to humans, and by using newly developed resources, genome-wide association studies in dog breeds are proving to be a powerful tool for unravelling complex disorders. This paper will review the literature on canine breed susceptibility to histiocytic sarcoma, osteosarcoma, haemangiosarcoma, mast cell tumours, lymphoma, melanoma, and mammary tumours including the recent advances in knowledge through molecular genetic, cytogenetic, and genome wide association studies. ... In our clinic (Cambridge, UK) ... cavalier King Charles spaniels ... are under-represented [for mast cell tumors]. ... Canine anal sac gland carcinoma (ASGC) is a relatively uncommon malignancy arising from the apocrine glands in the walls of the anal sacs. This tumour is invasive and metastatic in nature and is often associated with a paraneoplastic hypercalcaemia. Although ASGC [anal sac gland carcinoma] may arise in any breed of dog the English cocker spaniel and to a lesser degree other spaniel types (English springer and cavalier King Charles) have been reported to be predisposed to development of this tumour."
Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers. Gretel Torres de la Riva, Benjamin L. Hart, Thomas B. Farver, Anita M. Oberbauer, Locksley L. McV Messam, Neil Willits, Lynette A. Hart. PLOSone. Feb. 2013. Excerpt: "Hemangiosarcoma is a cancer that is affected by neutering in females. A study of cardiac tumors in dogs found that cardiac HSA for spayed females was greater than 4 times that of intact females. A study on splenic HSA found the spayed females had more than 2 times the risk of developing this tumor as intact females. Neither of these studies separated early- versus late-spayed females with regard to increased risk, and neither focused on just one breed. A study on the epidemiology of LSA (lymphoma) in dogs, for comparison with human lymphoma, found that intact females had a significantly lower risk of developing this cancer than neutered females or neutered males or intact males. Another cancer of concern is prostate cancer, which occurs in neutered males about four times as frequently as in intact males. A study on cutaneous mast cell tumors (MCT) in several dog breeds, including the Golden Retriever, examined risk factors such as breed, size, and neuter status. Although early versus late neutering was not considered, the results showed a significant increase in frequency of MCT in neutered females; four times greater than that of intact females. In contrast to the rather strong evidence for neutering males and/or females as a risk factor for OSA, HSA, LSA, MCT, and prostate cancer, evidence for neutering as protection against a dog acquiring one or more cancers is weak. The most frequently mentioned is mammary cancer (MC). However, a recent systematic review of published work on neutering and mammary tumors found the evidence that neutering reduces the risk of mammary neoplasia to be weak, at best."
Breed predispositions in canine mast cell tumour: A single centre experience in the United Kingdom. James Warland, Jane Dobson. Vet.J. April 2013. Quote: "Genetic factors play a major role in carcinogenesis. Many breeds have been reported to be predisposed to mast cell tumour (MCT) development using various methods and diverse control populations. A database of 222 dogs with MCT seen at a UK university referral hospital was compared to three control populations, namely, an insured population of UK dogs, registrations with the UK Kennel Club and other dogs seen through the same hospital. Odds ratios were calculated for each breed. Boxers, Labradors, Golden Retrievers and Staffordshire Bull Terriers appeared predisposed to MCT development. English Springer Spaniels, English Cocker Spaniels, German Shepherd Dogs, West Highland White Terriers and Cavalier King Charles Spaniels were underrepresented."
Serum thymidine kinase 1 and C-reactive protein as biomarkers for screening clinically healthy dogs for occult disease. K. A. Selting, C. R. Sharp, R. Ringold, J. Knouse. Vet. & Comparative Oncology. 2013. Quote: "Thymidine kinase (TK1) is a biomarker that correlates well with diagnosis and prognosis in certain canine cancers. Canine C-reactive protein (cCRP) is a widely accepted marker of inflammation correlated with increased risk and severity of various diseases. We evaluated serum TK1 and cCRP concentrations in apparently healthy dogs (n=360). All dogs were followed up for a minimum of 6months by health questionnaire. All dogs with cancer were identified using a proprietary dual-biomarker algorithm [termed Neoplasia Index (NI)]. Specificity of positive NI is 0.91 and high positive is 0.98. All-cause mortality was 20% in dogs with elevated cCRP and 3% in dogs with low cCRP. The performance of serum TK1 and cCRP as tools for screening for occult cancer is improved when evaluated together. Serum TK1 and cCRP (unified in the NI) are useful in the screening of occult canine cancer. cCRP is useful in screening for other serious diseases."
Canine Melanoma Vaccine. Heather Wilson-Robles. Clinicians Brief. August 2013:15-16. Quote: "Malignant melanoma is the most common malignant oral tumor in dogs, but it can also occur in other locations (eg, nail bed, eye, perineum, nasal cavity, GI tract, skin). ... Oncept (Merial, petcancervaccine.com), immunotherapy labeled for dogs with stage II or III oral melanoma, can help achieve local disease control.4 This therapy uses an orthologous DNA (different species) vaccine against tyrosinase, a melanosomal glycoprotein needed for melanin synthesis, to induce an antityrosinase immune response.5 Tyrosinase has been overexpressed in melanomas of various species.6-8 Although the human tyrosinase protein differs enough from the canine tyrosinase protein to allow human tyrosinase protein stimulation of an immune response in canine patients, in some cases the human tyrosinase protein is similar enough to the canine tyrosinase protein that the immune response is effective against canine melanoma cells."
Successful transendoscopic oesophageal mass ablation in two dogs with Spirocerca lupi associated oesophageal sarcoma. E. Yas, G. Kelmer, A. Shipov, J. Ben-Oz and G. Segev. J.Sm.Anim.Pract. Sept. 2013;54(9):495-498. Quote: "This report describes two cases of oesophageal tumours managed by transendoscopic neodymium:yttrium-aluminum-garnet laser ablation and polypectomy snare electrocautery. ... [including] A 4-year-old, neutered male, Cavalier King Charles spaniel ... In each dog oesophagoscopy revealed caudal oesophageal masses, suspected to be Spirocerca lupi-induced oesophageal neoplasia. To resect the masses, transendoscopic neodymium:yttrium-aluminum-garnet laser ablation was used in the first case and polypectomy snare electrocautery in the second. Recovery was uneventful. Histopathology was consistent with oesophageal fibrosarcoma and osteosarcoma in each case, respectively. Follow-up oesophagoscopy revealed apparently healthy oesophageal tissue except for focal scar tissue in the first case. Transendoscopic laser ablation and polypectomy snare electrocautery is a potential non-invasive, cost effective alternative for surgical oesophageal mass resection."
Canine tonsillar Squamous cell carcinoma. Isabelle Desmas. Vet. Ireland J. December 2013;3(12):654-657. Quote: Canine tonsillar squamous cell carcinoma is an uncommon disease, characterised by rapid growth and aggressive infiltration of the underlying tissues. Primary tonsillar cancer is called TSCC1. Whatever the treatment used, it is generally regarded to carry a poor prognosis. The metastatic rate is around 73%, the disease generally spreads to the regional lymph nodes and to the lungs. Treatment approach includes surgery, radiation therapy, chemotherapy and symptomatic treatment, or any combination of these approaches. Multimodality approach is indicated given the high aggressiveness of this type of cancer. All treatment confounded but keeping a multimodality treatment approach, the median survival time is around six months. Without any treatment, an absence of control of the primary disease will lead to euthanasia in one or two months. (Photo: Lymphadenopathy of the right submandibular lymph node in a Cavalier King Charles with a right-sided tonsillar squamous cell carcinoma.)
Extranodal lymphoma with peripheral nervous system involvement in a dog. Ueno H, Miyoshi K, Fukui S, Kondo Y, Matsuda K, Uchide T. J.Vet.Med.Sci. May 2014;76(5):723-727. Quote: "An 8-year-old neutered female Cavalier King Charles Spaniel was evaluated for progressing right forelimb lameness. Upon magnetic resonance imaging, the right-sided radius nerves and the caudal brachial plexus were swelled. The histological and molecular biological diagnosis of partial the C8 spinal nerve was T-cell lymphoma. Co-administration of lomustine and irradiation was started. However, this therapy was ineffective. At necropsy, neoplastic tissues were seen extending into the subarachnoid space of the spinal cord, the liver, pancreas and kidneys as gross findings. A large mass was also identified occupying the caudal thorax. Histologic findings included infiltration in these organs and mass by neoplastic lymphocytes. To date, involvement of peripheral nerves (neurolymphomatosis) is rarely reported in veterinary species."
Evaluation of the risk and age of onset of cancer and behavioral disorders in gonadectomized Vizslas. M. Christine Zink, Parvene Farhoody, Samra E. Elser, Lynda D. Ruffini, Tom A. Gibbons, Randall H. Rieger. JAVMA Feb. 2014;244(3):309-319. Quote: "Objective: To investigate associations between age at gonadectomy and estimated risk or age at diagnosis of neoplastic and behavioral disorders in Vizslas. Design: Retrospective cohort study. Animals: 2,505 Vizslas born between 1992 and 2008. Procedures: Data on demographics, gonadectomy status, and age at diagnosis of disease or disorder were obtained with an anonymous online survey and analyzed. Results: Dogs gonadectomized at ≤ 6 months, between 7 and 12 months, or at > 12 months of age had significantly increased odds of developing mast cell cancer, lymphoma, all other cancers, all cancers combined, and fear of storms, compared with the odds for sexually intact dogs. Females gonadectomized at ≤ 12 months of age and males and females gonadectomized at > 12 months of age had significantly increased odds of developing hemangiosarcoma, compared with the odds for sexually intact dogs. Dogs gonadectomized at ≤ 6 months of age had significantly increased odds of developing a behavioral disorder. The younger the age at gonadectomy, the earlier the mean age at diagnosis of mast cell cancer, cancers other than mast cell, hemangiosarcoma, lymphoma, all cancers combined, a behavioral disorder, or fear of storms. (Mast cell cancer: 3.5 times higher incidence in neutered male and female dogs, independent of age at the time of neutering. Hemangiosarcoma: 9.0 times higher incidence in neutered females compared to nonneutered females, independent of age at the time spaying was performed. No difference in incidence of this disease was found for neutered versus nonneutered males. Lymphoma (lymphosarcoma): 4.3 times higher incidence in neutered male and female dogs, independent of age at the time of neutering. Other types of cancer: 5.0 times higher incidence in neutered male and female dogs. The younger a dog was at the time of neutering the younger the age of the dog at the time the cancer was diagnosed. All cancers combined: 6.5 times higher incidence of cancer in neutered females compared to nonneutered females; 3.6 times higher incidence of cancer in neutered males compared to nonneutered males.) Conclusions and Clinical Relevance: Additional studies are needed on the biological effects of removing gonadal hormones and on methods to render dogs infertile that do not involve gonadectomy. Veterinarians should discuss the benefits and possible adverse effects of gonadectomy with clients, giving consideration to the breed of dog, the owner's circumstances, and the anticipated use of the dog."
Acupuncture and Herbals for Cancers: Evidence-Based Clinical Application. Huisheng Xie. Chi Institute. October 2014. Quote: "Cancer is the most common natural cause of death in dogs and cats in the United States. About 45% of dogs that live to 10 years or older die of cancer. The most common cancers in pets are lymphoma, mammary tumors/cancer, mast cell tumor (MCT), hemangiosarcoma, soft tissue sarcomas, melanoma, squamous cell carcinoma (SCC) and osteosarcoma. Traditional Chinese Medicine (TCM) has been used for the diagnosis and treatment of tumors since the Warring States Period (475 to 221 BC), when 'Ling Shu Jing' (Miraculous Pivot) stated 'the tumor was caused by the pathological factors which had stayed in the body over a long time'. Clinical evidence indicates that acupuncture and herbal medicine can benefit for the treatment of cancer in dogs and people. This paper reviews the acupuncture and Chinese herbals for the treatment or adjunct treatment of cancers, and the possible mechanism of actions."
Clinical systemic lupeol administration for canine oral malignant melanoma. Inoru Yokoe, Kazuo Azuma, Keishi Hata, Toshiyuki Mukaiyama, Takahiro Goto, Takeshi Tsuka, Tomohiro Imagawa, Norihiko Itoh, Yusuke Murahata, Tomohiro Osaki, Saburo Minami, Yoshiharu Okamoto. Molecular & Clinical Oncology. Jan. 2015;3(1):89-92. Quote: "Canine oral malignant melanoma (COMM) is the most common and aggressive malignant tumor in dogs. Lupeol is a triterpene extracted from various fruits and vegetables that reportedly inhibits melanoma cell proliferation in vitro and in vivo. In this study, the efficacy of subcutaneous lupeol for spontaneous COMM was evaluated. A total of 11 dogs (3, 5 and 3 dogs diagnosed with clinical stage I [including a 17 year old cavalier King Charles spaniel], II and III melanoma, respectively) were evaluated. Subcutaneous lupeol (10 mg/kg) was administered postoperatively at various time points to treat these 11 COMM cases. Of the 11 subjects, 7 [including the CKCS] exhibited no local recurrence 180 days postoperatively and no severe adverse effects were observed in any of the cases. Furthermore, no distant metastasis was observed during the experimental period. Therefore, systemic lupeol may prevent local tumor progression and distant metastasis and may be a novel adjuvant treatment for the treatment of COMM.
Before & After: Cavalier King Charles Gets Second Chance After Extensive Surgery to Remove Tumors. Sharon Ostermann. Tails of a Shelter Vet. March 2014. Quote: An adorable 12-year-old Cavalier King Charles Spaniel came to us at San Jose Animal Care & Services with multiple problems. The most obvious problem was the large mass that was on the front right of her chest. Though her long locks covered and concealed much of her body, we also found another mass on her belly and a large umbilical hernia. Like many Cavalier King Charles Spaniels, this little girl also had a heart murmur. ... The small mass was a benign mixed tumor that was completely removed and not likely to come back. The larger mass was a mammary adenocarcinoma (mammary tumor) (see photo at right) that was completely removed but showed evidence that it might regrow in the future. I was definitely concerned about this given how large and involved the mass was.
Management of canine corneal squamous cell carcinoma with lamellar keratectomy and strontium 90 plesiotherapy: 3 cases. Jessica C. Nevile, Simon D. Hurn, Andrew G.Turner, Christina McGowan. Vet. Ophth. May 2015;18(3):254-260. Quote: "Purpose: To report three cases of canine corneal squamous cell carcinoma (SCC) treated with strontium 90 beta radiation as an adjunct to surgical excision. A 15-year-old Cavalier King Charles Spaniel was presented with a 4 mm diameter axial whitish pink raised corneal mass OS. Methods: Corneal SCC was excised with lamellar keratectomy. This was followed by local application of strontium 90 beta radiation. Results: Available case follow-up times range from 3 to 50 months. One case suffered a recurrence 5 months following initial excision and strontium 90 treatment. Conclusion and discussion: Strontium 90 beta radiation has been used extensively as an adjunctive treatment for equine corneal SCC and in other canine ocular tumors; however, there is a paucity of information regarding use in canine corneal SCC. The cases presented here suggest its use following keratectomy may be helpful in preventing disease recurrence. At the dosage used, severe adverse effects were not observed."
Allogeneic hematopoietic cell transplantation in a dog with acute large granular lymphocytic leukemia. Suter SE, Hamilton MJ, Sullivan EW, Venkataraman GM. J Am Vet Med Assoc. May 2015;246(9):994-997. Quote: "Case Description: A 3-year-old 10-kg (22-lb) neutered male Cavalier King Charles Spaniel was referred because of an episode of acute vomiting and diarrhea. Clinical Findings: On physical examination, mild splenomegaly and prominent submandibular and popliteal lymph nodes were detected. Complete blood cell count revealed a high WBC count, characterized by a moderate lymphocytosis with 62% unclassified cells and severe thrombocytopenia with macroplatelets. On cytologic evaluation, the unclassified cells were described as large, neoplastic lymphoid cells containing a large nucleus with lacy chromatin and a large amount of blue vacuolated cytoplasm containing sparse, very fine azurophilic granules. A diagnosis of acute large granular lymphocytic leukemia of splenic origin was made. Treatment and Outcome: Following induction chemotherapy, the affected dog underwent allogeneic hematopoietic cell transplantation with dog leukocyte antigen-matched CD34+ cells harvested from a sibling of the same litter. Chimerism analysis revealed full donor engraftment within 2 weeks after transplantation that remained stable for at least 2 years, with the dog remaining apparently healthy at home. Clinical Relevance: Acute leukemias in dogs are rapidly fatal diseases. If an appropriate donor can be located, allogeneic hematopoietic cell transplantation may offer a feasible treatment, although peripheral blood CD34+ cell harvesting requires the availability of cell separator machines and management of graft-versus-host disease with immunosuppressive agents."
Partial retraction: Allogeneic hematopoietic cell transplantation in a dog with acute large granular lymphocytic leukemia. JAVMA August 2015;247(3):299. Quote: The article “Allogeneic hematopoietic cell transplantation in a dog with acute large granular lymphocytic leukemia” describes successful (ie, full donor chimerism approximately 2 weeks after transplantation and survival for > 2 years) allogeneic hematopoietic cell transplantation (HCT) in a 3-year-old Cavalier King Charles Spaniel in which a clinical diagnosis of acute large granular lymphocytic (LGL) leukemia had been made. At the time of case management, the authors made a diagnosis of acute LGL leukemia on the basis of clinical signs, initial CBC results (ie, WBC count of 24,200 WBCs/μL, consisting of 23% neutrophils, 12% lymphocytes, 2% monocytes, 1% eosinophils, and 62% unclassified, large, mononuclear cells with lightly vacuolated cytoplasm, a large nucleus, lacy chromatin, and a large indistinct nucleolus), and response to induction chemotherapy. In retrospect and following a full review of the medical record, it appears that a definitive diagnosis could not be reached in this case. Therefore, the conclusions that this case provides evidence that “allogeneic HCT is a realistic treatment option for dogs with acute leukemia,” that the report documents the first use of allogeneic HCT “for the treatment of a client-owned dog with acute LGL leukemia,” and that the report suggests that “use of allogeneic HCT to treat acute leukemias in dogs will provide a considerable clinical benefit over chemotherapy alone” are retracted by agreement of the editors, authors, and university. The conclusion that allogeneic HCT may be a feasible treatment in dogs remains unchanged.
Exome sequencing of lymphomas from three dog breeds reveals somatic mutation patterns reflecting genetic background. Ingegerd Elvers, Jason Turner-Maier, Ross Swofford, Michele Koltookian, Jeremy Johnson, Chip Stewart, Cheng-Zhong Zhang, Steven E Schumacher, Rameen Beroukhim, Mara Rosenberg, Rachael Thomas, Evan Mauceli, Gad Getz, Federica Di Palma, Jaime F Modiano, Matthew Breen, Kerstin Lindblad-Toh, Jessica Alföldi. Genome Res. September 2015. Quote: "Lymphoma is the most common hematological malignancy in developed countries. Outcome is strongly determined by molecular subtype, reflecting a need for new and improved treatment options. Dogs spontaneously develop lymphoma, and the predisposition of certain breeds indicates genetic risk factors. Using the dog breed structure, we selected three lymphoma predisposed breeds developing primarily Tcell (boxer), primarily B-cell (cocker spaniel), and with equal distribution of B and T-cell lymphoma (golden retriever), respectively. We investigated the somatic mutations in B- and T-cell lymphomas from these breeds by exome sequencing of tumor and normal pairs. Strong similarities were evident between B-cell lymphomas from golden retrievers and cocker spaniels, with recurrent mutations in TRAF3-MAP3K14 (28% of all cases), FBXW7 (25%), and POT1 (17%). The FBXW7 mutations recurrently occur in a specific codon; the corresponding codon is recurrently mutated in human cancer. In contrast, T-cell lymphomas from the predisposed breeds, boxers and golden retrievers, show little overlap in their mutation pattern, sharing only one of their 15 most recurrently mutated genes. Boxers, which develop aggressive T-cell lymphomas, are typically mutated in the PTEN-mTOR pathway. T-cell lymphomas in golden retrievers are often less aggressive and their tumors typically showed mutations in genes involved in cellular metabolism. We identify genes with known involvement in human lymphoma and leukemia, genes implicated in other human cancers, as well as novel genes that could allow new therapeutic options."
Canine indolent and aggressive lymphoma: clinical spectrum with histologic correlation. L. Aresu, V. Martini, F. Rossi, M. Vignoli, M. Sampaolo, A. Aricò, P. Laganga, A. Pierini, P. Frayssinet, R. Mantovani, L. Marconato. Vet. & Comp. Oncology. December 2015;13(4):348-362. Quote: "Sixty-three dogs with newly diagnosed lymphoma underwent complete staging and received the same chemotherapy. Diffuse large B-cell lymphoma was the leading histotype (44.4%), followed by peripheral T-cell lymphoma (20.6%). Indolent lymphomas accounted for 30.2% of cases. Most dogs with aggressive B-cell lymphoma had stage IV disease. Dogs with indolent and aggressive T-cell lymphoma had more often stage V disease and were symptomatic. Liver and bone marrow were predominantly involved in B-cell and T-cell lymphoma, respectively. The clinical stage was significantly related to substage, sex and total lactic dehydrogenase (LDH) levels. Aggressive B-cell lymphomas were more likely to achieve remission. Median survival was 55 days for aggressive and indolent T-cell lymphoma, 200 and 256 days for indolent and aggressive B-cell lymphoma, respectively. The prognosis of advanced indolent lymphoma does not appear to be appreciably different from that of aggressive disease. Familiarity with the various histotypes is critical to make the correct diagnosis and drive therapy."
High-throughput mRNA and miRNA profiling of epithelial-mesenchymal transition in MDCK cells. Priyank Shukla, Claus Vogl, Barbara Wallner, Doris Rigler, Mathias Müller, Sabine Macho-Maschler. BMC Genomics. November 2015;16:944. Quote: "Background: Epithelial-mesenchymal transition (EMT) is an important process in embryonic development, especially during gastrulation and organ formation. Furthermore EMT is widely observed in pathological conditions, e.g., fibrosis, tumor progression and metastasis. Madin-Darby Canine Kidney (MDCK) cells are widely used for studies of EMT and epithelial plasticity. MDCK cells show an epithelial phenotype, while oncogenic Ras-transformed MDCK (MDCK-Ras) cells undergo EMT and show a mesenchymal phenotype. Methods: RNA-Seq and miRNA-Seq analyses were performed on MDCK and MDCK-Ras cells. Data were validated by qRT-PCR. Gene signature analyses were carried out to identify pathways and gene ontology terms. For selected miRNAs target prediction was performed. Results: With RNA-Seq, mRNAs of approximately half of the genes known for dog were detected. These were screened for differential regulation during Ras-induced EMT. We went further and performed gene signature analyses and found Gene Ontology (GO) terms and pathways important for epithelial polarity and implicated in EMT. Among the identified pathways, TGFβ1 emerged as a central signaling factor in many EMT related pathways and biological processes. With miRNA-Seq, approximately half of the known canine miRNAs were found expressed in MDCK and MDCK-Ras cells. Furthermore, among differentially expressed miRNAs, miRNAs that are known to be important regulators of EMT were detected and new candidates were predicted. New dog miRNAs were discovered after aligning our reads to that of other species in miRBase. Importantly, we could identify 25 completely novel miRNAs with a stable hairpin structure. Two of these novel miRNAs were differentially expressed. We validated the two novel miRNAs with the highest read counts by RT-qPCR. Target prediction of a particular novel miRNA highly expressed in mesenchymal MDCK-Ras cells revealed that it targets components of epithelial cell junctional complexes. Combining target prediction for the most upregulated miRNAs and validation of the targets in MDCK-Ras cells with pathway analysis allowed us to identify two novel pathways, e.g., JAK/STAT signaling and pancreatic cancer pathways. These pathways could not be detected solely by gene set enrichment analyses of RNA-Seq data. Conclusion: With deep sequencing data of mRNAs and miRNAs of MDCK cells and of Ras-induced EMT in MDCK cells, differentially regulated mRNAs and miRNAs are identified. Many of the identified genes are within pathways known to be involved in EMT. Novel differentially upregulated genes in MDCK cells are interferon stimulated genes and genes involved in Slit and Netrin signaling. New pathways not yet linked to these processes were identified. A central pathway in Ras induced EMT is TGFβ signaling, which leads to differential regulation of many target genes, including miRNAs. With miRNA-Seq we identified miRNAs involved in either epithelial cell biology or EMT. Finally, we describe completely novel miRNAs and their target genes."
Mutation of p53 Gene and Its Correlation with the Clinical Outcome in Dogs with Lymphoma. A. Koshino, Y. Goto-Koshino, A. Setoguchi, K. Ohno, H. Tsujimoto. J. Vet. Intern. Med. December 2015. Quote: "Background: p53 plays a key role in the apoptotic event induced by chemotherapeutic agents. Mutation of p53 gene has been observed in various spontaneous tumors in humans and is associated with a poor prognosis. p53 abnormalities have been evaluated in several tumors in dogs; however, the association of p53 gene mutation with clinical outcome in dogs with lymphoma has not been documented. Hypothesis/Objectives: The aim of this study was to examine p53 mutation in canine lymphoma cells and its association with the clinical outcome. Animals: Forty-three dogs [including 2 cavalier King Charles spaniels] with previously untreated high-grade lymphoma referred to the University of Tokyo were included in this study. Methods: Prospective cohort study. We examined p53 gene (exon 4–8) mutation in the tumor tissues from 43 dogs with lymphoma using PCR-SSCP (polymerase chain reaction – single-strand conformational polymorphism) analysis, followed by nucleotide sequencing of the abnormal bands. Results: Of the 43 dogs, 7 dogs (16%) had p53 mutation, whereas 36 dogs (84%) were devoid of p53 mutation. Overall response rate after remission induction was significantly lower (33% versus 88%, P = .002) in dogs with lymphomas having p53 mutation than those with lymphomas devoid of p53 mutation. Overall survival time was significantly shorter (67 days versus 264 days, P = .004) in dogs with lymphoma with p53 mutation than those with lymphoma retaining wild-type p53. Conclusion and Clinical Importance: Mutations of p53 gene were detected in a proportion of canine lymphoma cells from untreated dogs and can be associated with a poor prognosis."
Lu-177-Labeled Zirconia Particles for Radiation Synovectomy. Andras Polyak, Lívia Naszályi Nagy, Eszter Drotár, Gabriella Dabasi, Róbert P. Jóba, Zita Pöstényi, Renata Mikolajczak, Attila Bóta, Lajos Balogh. Cancer Biotherapy and Radiopharmaceuticals. December 2015;30(10). Quote: "The present article describes the preparation of β-emitter lutetium-177-labeled zirconia colloid and its preliminary physicochemical and biological evaluation of suitability for local radionuclide therapy. ... An 11-year-old spayed Cavalier King Charles Spaniel was referred to the Institute with chronic, destructive, therapy-resistant osteoarthritis in the left hock joint. ... The new 177Lu-labeled therapeutic radiopharmaceutical candidate was based on the synthesis mode of a previously described zirconia nanoparticle system. The size and shape of the developed radiopharmaceutical compound were observed through a scanning electron microscope and dynamic light scattering methods. The radiocolloid had a 1.7 μm mean diameter and showed high in vitro radiochemical and colloid size stability at room temperature and during the blood sera stability test. After the in vitro characterizations, the product was investigated in the course of the treatment of a spontaneously diseased dog veterinary patient's hock joint completed with single-photon emission computed tomography (SPECT) imaging follow-up measurements and a dual-isotope SPECT imaging tests with conventional 99mTc-methanediphosphonic acid bone scintigraphy. In the treated dog, no clinical side-effects or signs of histopathological changes of the joints were recorded during the treatment. SPECT follow-up studies clearly and conspicuously showed the localization of the 177Lu-labeled colloid in the hock joint as well as detectable but negligible leakages of the radiocolloid in the nearest lymph node. On the basis of biological follow-up tests, the orthopedic team assumed that the 177Lu-labeled zirconia colloid-based local radionuclide therapy resulted in a significant and long-term improvement in clinical signs of the patient without any remarkable side-effects."
Lymphocytic thymoma in cavalier King Charles spaniel - case report and review. G. Simeonova, V. Nedev, R. Simeonov. Trakia J. of Sci. 2015;13(Suppl. 2):268-273. Quote: "A clinical case of thymoma in 6 month old, male, cavalier King Charles spaniel was described. The patient was brought to the Small Animal Clinic of Veterinary faculty at Trakia University, Stara Zagora in order to be evaluated by means of electroretinography (ERG) because of vision loss and difficulties in orientation in unfamiliar surroundings. Physical examination did not reveal any disturbances in vital parameters neither in retinal function. As complications occurred during recovery from general anaesthesia more detailed investigations were performed and the diagnosis thymoma was made. It was confirmed pathohistologically. Thymoma is an extremely rare tumor in dogs, especially in cavalier King Charles spaniels. The unusual manifestation of the disease as well as its very rare distribution among dogs was the reason to give a problem consideration."
Histological and immunohistochemical evaluation of stroma variations and their 4 correlation with the Ki-67 index and expressions of glucose transporter 1 and 5 monocarboxylate transporter 1 in canine thyroid C-cell carcinomas. Yoshio Kawamura, Hiroko Mizooku, Minoru Okamoto, Kazuya Matsuda, Tetsuo Omachi, Kazuko Hirayama, Tsuyoshi Kadosawa, Hiroyuki Taniyama. J. Vet. Med. Sci. January 2016. Quote: "Canine thyroid C-cell carcinomas (CTCCs) are malignant tumors derived from calcitonin-producing C-cells of the thyroid gland. This study aimed to investigate the histological diversity of CTCCs from the viewpoint of stroma variations and to investigate their components by histological and immunohistochemical analysis including semiquantitative analysis of the density of microvessels (MVs) and α-SMA-positive cell count. Moreover, we examined whether the variations correlated with the Ki-67 index and expressions of glucose transporter 1 (GLUT-1) and monocarboxylate transporter 1 (MCT-1). Three stroma types (reticular, R, nest, N, and trabecular, T) were observed in CTCCs and 21 cases were divided into 3 variations based on their combinations: mixed R and N (R/N) (n=7), simple N (n=7) and mixed T and N (T/N) (n=7). [One cavalier King Charles spaniel: female aged 10 years, tumor diameter: 4 cm., period to surgical treatment: 300 days.] Immuno-histochemically, stroma types depended on morphological features of α-SMA/fibronectin/laminin/collagen type IV-positive stroma cells. The density of MVs in R/N tended to be highest, and the density of those in N was significantly higher than the density of those in T/N (P=0.028). The α-SMA-positive cell count for N tended to be the lowest among the 3 variations. The Ki-67 index for R/N was significantly higher than those of the other variations (vs. N, P=0.007; vs. T/N, P=0.03), and that for T/N tended to be higher than that for N. Although there were no significant differences, GLUT-1 and MCT-1 expressions tended to be low in N. We concluded that stroma variations reflect tumor cell proliferation and expressions of GLUT-1 and MCT-1 in CTCCs."
Third eyelid gland neoplasms of dogs and cats: a retrospective histopathologic study of 145 cases. D. Dustin Dees, Charles S. Schobert, Richard R. Dubielzig, Timothy J. Stein. Vet. Ophthalmology. March 2016;19(2):138-143. Quote: "Purpose: To describe the various types of primary neoplasms affecting the third eyelid (TEL) gland of dogs and cats. Methods: A retrospective search of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) database was performed. Veterinary ophthalmologists, primary care veterinarians, and, when appropriate, owners were contacted for patient follow-up information. Patient data points collected included species, age, sex, breed, laterality, tumor type, surgical margins, recurrence, metastasis, and length of follow-up. Results: A total of 127 canine [including a cavalier King Charles spaniel] and 18 feline cases met the inclusion criteria. The most common canine TEL gland tumor was adenocarcinoma (n = 108; 85.0%) followed by adenoma (n = 18; 14.2%) and squamous cell carcinoma (SCC) (n = 1; 0.8%). For canine cases with follow-up information available (n = 62), 8.1% had confirmed or suspected metastasis and 11.3% had confirmed or suspected local recurrence of disease. The most common feline TEL gland tumor was adenocarcinoma (n = 15; 83.3%) followed by SCC (n = 3; 16.7%). For feline cases with follow-up information available (n = 9), 40.0% had confirmed or suspected metastasis and 30.0% had confirmed or suspected local recurrence of disease. Conclusions: This study determined that adenocarcinoma was the most common third eyelid gland tumor in both dogs and cats. The overall survival times were less, and metastatic occurrence and recurrence rates appeared to be higher for feline tumors as compared to those diagnosed in dogs. This is the first report of SCC originating from glandular ductular epithelium."
Canine tumor development and crude incidence of tumors by breed based on domestic dogs in Gifu Prefecture. Satoshi Komazawa, Hiroki Sakai, Yusuke Itoh, Mifumi Kawabe, Mami Murakami, Takashi Mori, Kohji Maruo. J. Vet. Med. Sci. May 2016. Quote: We analyzed the status of tumor development in dogs by breed based on tumor cases that presented to the Department of Veterinary Pathology of the Gifu University for diagnostic examinations over eight years (2005–2012). We also calculated the crude incidence of tumors in dogs by breed based on the results of a survey conducted in 2011 in Gifu Prefecture. The most common sites of tumor development included the skin, digestive organs, and mammary glands. Smaller dogs showed a tendency to have a higher incidence of breast tumors. We thus identified dog breeds with a higher crude incidence of tumors (Bernese mountain dog, golden retriever, corgi, etc.) and those with a lower crude incidence of tumors (Pomeranian, poodle, Chihuahua, etc.). Unlike the current trends for domestic dogs in the US and Europe, Japan has a higher number of small dogs as pets; it is therefore necessary to develop a policy for canine cancer specific to Japan. ... Smaller dog breeds had greater proportion of 176 breast tumors, which accounted for ... 41.2% in Cavalier King Charles Spaniel (CK). ... Mast cell tumors have been found ... with a lower frequency for such tumors were also revealed to be CK ... [Number of cavaliers with tumors: 34].
Evaluation of the factors contributing to long-term survival in canine tonsillar squamous cell carcinoma. J Grant, S North. Australian Vet. J. June 2016;94(6):197-202. Quote: Objectives: To identify any prognostic factors that may be associated with the long-term survival of dogs diagnosed with tonsillar squamous cell carcinoma (TSCC). Methods: The medical records of 15 dogs treated for TSCC were reviewed retrospectively. The signalment, presenting signs, clinical stage, treatments and outcome were documented. Results: The overall median survival time (MST) of the dogs in the study was 243 days. There was a 1-and 2-year survival of 40% and 20%, respectively. The results of initial staging had a signiﬁcant effect on survival, as dogs with only one tonsil affected and no evidence of metastatic disease had a longer MST (637.5 days) than the dogs with local (MST: 134 days) or distant (MST: 75 days) metastatic disease or bilateral tonsillar involvement at the time of initial presentation. Prolonged survival times were reported for dogs undergoing surgery and adjunctive chemotherapy (MST: 464.5 days) for treatment of their TSCC. Clinical signiﬁcance This is the ﬁrst veterinary study demonstrating an association between prognosis of patients with TSCC and stage at the time of presentation, with long survival times demonstrated for dogs with early-stage disease following an initial treatment protocol that included surgery and chemotherapy. There was no clear association between long survival and additional surgeries for progressive disease; however; further investigation is warranted. ... Population data: Of the 15 dogs included in the study, 11 (73%) were male and 4 (27%) were female. The median age at the time of diagnosis was 10.5 years (mean: 10.6 years; range: 7–14) (Table 2). There was a mixture of breeds: 5 collies (Border Collie, Rough Collie and Bearded Collie), 3 spaniels (Springer and Cavalier King Charles Spaniels), 2 West Highland White Terriers, 2 Bichon Frise, 1 Lowchen, 1 Staffordshire Bull Terrier and 1 Saluki. ... [details of CKCS: Age: 9 yrs; Sex: female, spayed; symptoms: gagging/dysphagia; contralateral tonsil: lymphoid hyperplasia (RHS); Stage: T3N1a; surgery: bilateral tonsillectomy; chemotherapy: Carboplatin: 300 mg/m² x 4 cycles + Postoperative adjunct Rx (hypofractionated: 9 Gy × 4 fractions): tonsils; Survival from diagnosis day: 779; Outcome: pulmonary carcinoma; intraoperative death. ... Although the diagnosis of TSCC continues to be associated with an extremely guarded prognosis, this is the ﬁrst study to demonstrate an association between early clinical stage at the time of diagnosis and survival. Prolonged survival in patients with only one tonsil affected at the time of diagnosis was achieved in patients undergoing initial treatment with surgery and chemotherapy, thus providing a strong argument for multimodality treatment. Larger studies into the effects of initial staging and treatment on long-term prognosis in patients with TSCC are required in the future to verify these preliminary ﬁndings.